fix_rigid.html
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fix_rigid.html
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			<p class="caption"><span class="caption-text">User Documentation</span></p>
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			<li class="toctree-l1"><a class="reference internal" href="Section_intro.html">1. Introduction</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_start.html">2. Getting Started</a></li>
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			<li class="toctree-l1"><a class="reference internal" href="Section_packages.html">4. Packages</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_accelerate.html">5. Accelerating LAMMPS performance</a></li>
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			<li class="toctree-l1"><a class="reference internal" href="Section_example.html">7. Example problems</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_perf.html">8. Performance & scalability</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_tools.html">9. Additional tools</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_modify.html">10. Modifying & extending LAMMPS</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_python.html">11. Python interface to LAMMPS</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_errors.html">12. Errors</a></li>
			<li class="toctree-l1"><a class="reference internal" href="Section_history.html">13. Future and history</a></li>
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			<p class="caption"><span class="caption-text">Index</span></p>
			<ul class="current">
			<li class="toctree-l1"><a class="reference internal" href="tutorials.html">Tutorials</a></li>
			<li class="toctree-l1"><a class="reference internal" href="commands.html">Commands</a></li>
			<li class="toctree-l1 current"><a class="reference internal" href="fixes.html">Fixes</a><ul class="current">
			<li class="toctree-l2"><a class="reference internal" href="fix_adapt.html">fix adapt command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_adapt_fep.html">fix adapt/fep command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_addforce.html">fix addforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_addtorque.html">fix addtorque command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_append_atoms.html">fix append/atoms command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_atc.html">fix atc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_atom_swap.html">fix atom/swap command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_atom.html">fix ave/atom command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_chunk.html">fix ave/chunk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_correlate.html">fix ave/correlate command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_correlate_long.html">fix ave/correlate/long command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_histo.html">fix ave/histo command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_histo.html#fix-ave-histo-weight-command">fix ave/histo/weight command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ave_time.html">fix ave/time command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_aveforce.html">fix aveforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_balance.html">fix balance command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_bond_break.html">fix bond/break command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_bond_create.html">fix bond/create command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_bond_swap.html">fix bond/swap command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_box_relax.html">fix box/relax command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_colvars.html">fix colvars command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_controller.html">fix controller command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_deform.html">fix deform command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_deform.html#fix-deform-kk-command">fix deform/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_deposit.html">fix deposit command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_drag.html">fix drag command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_drude.html">fix drude command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_drude_transform.html">fix drude/transform/direct command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_drude_transform.html#fix-drude-transform-inverse-command">fix drude/transform/inverse command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_dt_reset.html">fix dt/reset command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_efield.html">fix efield command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ehex.html">fix ehex command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_enforce2d.html">fix enforce2d command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_eos_cv.html">fix eos/cv command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_eos_table.html">fix eos/table command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_eos_table_rx.html">fix eos/table/rx command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_evaporate.html">fix evaporate command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_external.html">fix external command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_flow_gauss.html">fix flow/gauss command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_freeze.html">fix freeze command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_gcmc.html">fix gcmc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_gld.html">fix gld command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_gle.html">fix gle command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_gravity.html">fix gravity command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_gravity.html#fix-gravity-omp-command">fix gravity/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_heat.html">fix heat command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_imd.html">fix imd command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_indent.html">fix indent command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ipi.html">fix ipi command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_langevin.html">fix langevin command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_langevin.html#fix-langevin-kk-command">fix langevin/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_langevin_drude.html">fix langevin/drude command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_langevin_eff.html">fix langevin/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lb_fluid.html">fix lb/fluid command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lb_momentum.html">fix lb/momentum command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lb_pc.html">fix lb/pc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lb_rigid_pc_sphere.html">fix lb/rigid/pc/sphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lb_viscous.html">fix lb/viscous command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_lineforce.html">fix lineforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_manifoldforce.html">fix manifoldforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_meso.html">fix meso command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_meso_stationary.html">fix meso/stationary command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_momentum.html">fix momentum command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_move.html">fix move command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_msst.html">fix msst command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_neb.html">fix neb command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html">fix nvt command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nvt-intel-command">fix nvt/intel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nvt-kk-command">fix nvt/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nvt-omp-command">fix nvt/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-npt-command">fix npt command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-npt-intel-command">fix npt/intel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-npt-kk-command">fix npt/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-npt-omp-command">fix npt/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nph-command">fix nph command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nph-kk-command">fix nph/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nph-omp-command">fix nph/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html">fix nvt/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html#fix-npt-eff-command">fix npt/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html#fix-nph-eff-command">fix nph/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nph_asphere.html">fix nph/asphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nph_asphere.html#fix-nph-asphere-omp-command">fix nph/asphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nph_body.html">fix nph/body command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nph_sphere.html">fix nph/sphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nph_sphere.html#fix-nph-sphere-omp-command">fix nph/sphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nphug.html">fix nphug command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nphug.html#fix-nphug-omp-command">fix nphug/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_npt_asphere.html">fix npt/asphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_npt_asphere.html#fix-npt-asphere-omp-command">fix npt/asphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_npt_body.html">fix npt/body command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_npt_sphere.html">fix npt/sphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_npt_sphere.html#fix-npt-sphere-omp-command">fix npt/sphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve.html">fix nve command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve.html#fix-nve-intel-command">fix nve/intel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve.html#fix-nve-kk-command">fix nve/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve.html#fix-nve-omp-command">fix nve/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_asphere.html">fix nve/asphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_asphere.html#fix-nve-asphere-intel-command">fix nve/asphere/intel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_asphere_noforce.html">fix nve/asphere/noforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_body.html">fix nve/body command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_eff.html">fix nve/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_limit.html">fix nve/limit command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_line.html">fix nve/line command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_manifold_rattle.html">fix nve/manifold/rattle command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_noforce.html">fix nve/noforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_sphere.html">fix nve/sphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_sphere.html#fix-nve-sphere-omp-command">fix nve/sphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nve_tri.html">fix nve/tri command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_asphere.html">fix nvt/asphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_asphere.html#fix-nvt-asphere-omp-command">fix nvt/asphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_body.html">fix nvt/body command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_manifold_rattle.html">fix nvt/manifold/rattle command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod.html">fix nvt/sllod command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod.html#fix-nvt-sllod-intel-command">fix nvt/sllod/intel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod.html#fix-nvt-sllod-omp-command">fix nvt/sllod/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod_eff.html">fix nvt/sllod/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sphere.html">fix nvt/sphere command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sphere.html#fix-nvt-sphere-omp-command">fix nvt/sphere/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_oneway.html">fix oneway command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_orient.html">fix orient/fcc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_orient.html#fix-orient-bcc-command">fix orient/bcc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_phonon.html">fix phonon command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_pimd.html">fix pimd command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_planeforce.html">fix planeforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_poems.html">fix poems</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_pour.html">fix pour command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_press_berendsen.html">fix press/berendsen command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_print.html">fix print command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_property_atom.html">fix property/atom command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qbmsst.html">fix qbmsst command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html">fix qeq/point command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-shielded-command">fix qeq/shielded command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-slater-command">fix qeq/slater command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-dynamic-command">fix qeq/dynamic command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-fire-command">fix qeq/fire command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq_comb.html">fix qeq/comb command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq_comb.html#fix-qeq-comb-omp-command">fix qeq/comb/omp command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq_reax.html">fix qeq/reax command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qeq_reax.html#fix-qeq-reax-kk-command">fix qeq/reax/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qmmm.html">fix qmmm command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_qtb.html">fix qtb command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_reax_bonds.html">fix reax/bonds command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_reax_bonds.html#fix-reax-c-bonds-command">fix reax/c/bonds command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_reaxc_species.html">fix reax/c/species command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_recenter.html">fix recenter command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_restrain.html">fix restrain command</a></li>
			<li class="toctree-l2 current"><a class="current reference internal" href="#">fix rigid command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nve-command">fix rigid/nve command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nvt-command">fix rigid/nvt command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-npt-command">fix rigid/npt command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nph-command">fix rigid/nph command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-small-command">fix rigid/small command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nve-small-command">fix rigid/nve/small command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nvt-small-command">fix rigid/nvt/small command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-npt-small-command">fix rigid/npt/small command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="#fix-rigid-nph-small-command">fix rigid/nph/small command</a><ul>
			<li class="toctree-l3"><a class="reference internal" href="#syntax">Syntax</a></li>
			<li class="toctree-l3"><a class="reference internal" href="#examples">Examples</a></li>
			<li class="toctree-l3"><a class="reference internal" href="#description">Description</a></li>
			<li class="toctree-l3"><a class="reference internal" href="#restrictions">Restrictions</a></li>
			<li class="toctree-l3"><a class="reference internal" href="#related-commands">Related commands</a></li>
			<li class="toctree-l3"><a class="reference internal" href="#default">Default</a></li>
			</ul>
			</li>
			<li class="toctree-l2"><a class="reference internal" href="fix_rx.html">fix rx command</a></li>
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			<li class="toctree-l2"><a class="reference internal" href="fix_setforce.html">fix setforce command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_setforce.html#fix-setforce-kk-command">fix setforce/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_shake.html">fix shake command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_shake.html#fix-rattle-command">fix rattle command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_shardlow.html">fix shardlow command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_smd.html">fix smd command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_smd_adjust_dt.html">fix smd/adjust_dt command</a></li>
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			<li class="toctree-l2"><a class="reference internal" href="fix_smd_setvel.html">fix smd/setvel command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_smd_wall_surface.html">fix smd/wall_surface command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_spring.html">fix spring command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_spring_chunk.html">fix spring/chunk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_spring_rg.html">fix spring/rg command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_spring_self.html">fix spring/self command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_srd.html">fix srd command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_store_force.html">fix store/force command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_store_state.html">fix store/state command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_temp_berendsen.html">fix temp/berendsen command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_temp_csvr.html">fix temp/csvr command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_temp_csvr.html#fix-temp-csld-command">fix temp/csld command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_temp_rescale.html">fix temp/rescale command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_temp_rescale_eff.html">fix temp/rescale/eff command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_tfmc.html">fix tfmc command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_thermal_conductivity.html">fix thermal/conductivity command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ti_rs.html">fix ti/rs command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ti_spring.html">fix ti/spring command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_tmd.html">fix tmd command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ttm.html">fix ttm command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_ttm.html#fix-ttm-mod-command">fix ttm/mod command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_tune_kspace.html">fix tune/kspace command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_vector.html">fix vector command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_viscosity.html">fix viscosity command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_viscous.html">fix viscous command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall.html">fix wall/lj93 command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-lj126-command">fix wall/lj126 command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-lj1043-command">fix wall/lj1043 command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-colloid-command">fix wall/colloid command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-harmonic-command">fix wall/harmonic command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_gran.html">fix wall/gran command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_piston.html">fix wall/piston command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_reflect.html">fix wall/reflect command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_reflect.html#fix-wall-reflect-kk-command">fix wall/reflect/kk command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_region.html">fix wall/region command</a></li>
			<li class="toctree-l2"><a class="reference internal" href="fix_wall_srd.html">fix wall/srd command</a></li>
			</ul>
			</li>
			<li class="toctree-l1"><a class="reference internal" href="computes.html">Computes</a></li>
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			<li class="toctree-l1"><a class="reference internal" href="angles.html">Angle Styles</a></li>
			<li class="toctree-l1"><a class="reference internal" href="dihedrals.html">Dihedral Styles</a></li>
			<li class="toctree-l1"><a class="reference internal" href="impropers.html">Improper Styles</a></li>
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			<div class="section" id="fix-rigid-command">
			<span id="index-0"></span><h1>fix rigid command</h1>
			</div>
			<div class="section" id="fix-rigid-nve-command">
			<h1>fix rigid/nve command</h1>
			</div>
			<div class="section" id="fix-rigid-nvt-command">
			<h1>fix rigid/nvt command</h1>
			</div>
			<div class="section" id="fix-rigid-npt-command">
			<h1>fix rigid/npt command</h1>
			</div>
			<div class="section" id="fix-rigid-nph-command">
			<h1>fix rigid/nph command</h1>
			</div>
			<div class="section" id="fix-rigid-small-command">
			<h1>fix rigid/small command</h1>
			</div>
			<div class="section" id="fix-rigid-nve-small-command">
			<h1>fix rigid/nve/small command</h1>
			</div>
			<div class="section" id="fix-rigid-nvt-small-command">
			<h1>fix rigid/nvt/small command</h1>
			</div>
			<div class="section" id="fix-rigid-npt-small-command">
			<h1>fix rigid/npt/small command</h1>
			</div>
			<div class="section" id="fix-rigid-nph-small-command">
			<h1>fix rigid/nph/small command</h1>
			<div class="section" id="syntax">
			<h2>Syntax</h2>
			<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">fix</span> <span class="n">ID</span> <span class="n">group</span><span class="o">-</span><span class="n">ID</span> <span class="n">style</span> <span class="n">bodystyle</span> <span class="n">args</span> <span class="n">keyword</span> <span class="n">values</span> <span class="o">...</span>
			</pre></div>
			</div>
			<ul>
			<li><p class="first">ID, group-ID are documented in <a class="reference internal" href="fix.html"><span class="doc">fix</span></a> command</p>
			</li>
			<li><p class="first">style = <em>rigid</em> or <em>rigid/nve</em> or <em>rigid/nvt</em> or <em>rigid/npt</em> or <em>rigid/nph</em> or <em>rigid/small</em> or <em>rigid/nve/small</em> or <em>rigid/nvt/small</em> or <em>rigid/npt/small</em> or <em>rigid/nph/small</em></p>
			</li>
			<li><p class="first">bodystyle = <em>single</em> or <em>molecule</em> or <em>group</em></p>
			<pre class="literal-block">
			<em>single</em> args = none
			<em>molecule</em> args = none
			<em>group</em> args = N groupID1 groupID2 ...
			N = # of groups
			groupID1, groupID2, ... = list of N group IDs
			</pre>
			</li>
			<li><p class="first">zero or more keyword/value pairs may be appended</p>
			</li>
			<li><p class="first">keyword = <em>langevin</em> or <em>temp</em> or <em>iso</em> or <em>aniso</em> or <em>x</em> or <em>y</em> or <em>z</em> or <em>couple</em> or <em>tparam</em> or <em>pchain</em> or <em>dilate</em> or <em>force</em> or <em>torque</em> or <em>infile</em></p>
			<pre class="literal-block">
			<em>langevin</em> values = Tstart Tstop Tperiod seed
			Tstart,Tstop = desired temperature at start/stop of run (temperature units)
			Tdamp = temperature damping parameter (time units)
			seed = random number seed to use for white noise (positive integer)
			<em>temp</em> values = Tstart Tstop Tdamp
			Tstart,Tstop = desired temperature at start/stop of run (temperature units)
			Tdamp = temperature damping parameter (time units)
			<em>iso</em> or <em>aniso</em> values = Pstart Pstop Pdamp
			Pstart,Pstop = scalar external pressure at start/end of run (pressure units)
			Pdamp = pressure damping parameter (time units)
			<em>x</em> or <em>y</em> or <em>z</em> values = Pstart Pstop Pdamp
			Pstart,Pstop = external stress tensor component at start/end of run (pressure units)
			Pdamp = stress damping parameter (time units)
			<em>couple</em> = <em>none</em> or <em>xyz</em> or <em>xy</em> or <em>yz</em> or <em>xz</em>
			<em>tparam</em> values = Tchain Titer Torder
			Tchain = length of Nose/Hoover thermostat chain
			Titer = number of thermostat iterations performed
			Torder = 3 or 5 = Yoshida-Suzuki integration parameters
			<em>pchain</em> values = Pchain
			Pchain = length of the Nose/Hoover thermostat chain coupled with the barostat
			<em>dilate</em> value = dilate-group-ID
			dilate-group-ID = only dilate atoms in this group due to barostat volume changes
			<em>force</em> values = M xflag yflag zflag
			M = which rigid body from 1-Nbody (see asterisk form below)
			xflag,yflag,zflag = off/on if component of center-of-mass force is active
			<em>torque</em> values = M xflag yflag zflag
			M = which rigid body from 1-Nbody (see asterisk form below)
			xflag,yflag,zflag = off/on if component of center-of-mass torque is active
			<em>infile</em> filename
			filename = file with per-body values of mass, center-of-mass, moments of inertia
			<em>mol</em> value = template-ID
			template-ID = ID of molecule template specified in a separate <a class="reference internal" href="molecule.html"><span class="doc">molecule</span></a> command
			</pre>
			</li>
			</ul>
			</div>
			<div class="section" id="examples">
			<h2>Examples</h2>
			<pre class="literal-block">
			fix 1 clump rigid single
			fix 1 clump rigid/small molecule
			fix 1 clump rigid single force 1 off off on langevin 1.0 1.0 1.0 428984
			fix 1 polychains rigid/nvt molecule temp 1.0 1.0 5.0
			fix 1 polychains rigid molecule force 15 off off off force 610 off off on
			fix 1 polychains rigid/small molecule langevin 1.0 1.0 1.0 428984
			fix 2 fluid rigid group 3 clump1 clump2 clump3 torque * off off off
			fix 1 rods rigid/npt molecule temp 300.0 300.0 100.0 iso 0.5 0.5 10.0
			fix 1 particles rigid/npt molecule temp 1.0 1.0 5.0 x 0.5 0.5 1.0 z 0.5 0.5 1.0 couple xz
			fix 1 water rigid/nph molecule iso 0.5 0.5 1.0
			fix 1 particles rigid/npt/small molecule temp 1.0 1.0 1.0 iso 0.5 0.5 1.0
			</pre>
			</div>
			<div class="section" id="description">
			<h2>Description</h2>
			<p>Treat one or more sets of atoms as independent rigid bodies. This
			means that each timestep the total force and torque on each rigid body
			is computed as the sum of the forces and torques on its constituent
			particles. The coordinates, velocities, and orientations of the atoms
			in each body are then updated so that the body moves and rotates as a
			single entity.</p>
			<p>Examples of large rigid bodies are a colloidal particle, or portions
			of a biomolecule such as a protein.</p>
			<p>Example of small rigid bodies are patchy nanoparticles, such as those
			modeled in <a class="reference internal" href="pair_gran.html#zhang"><span class="std std-ref">this paper</span></a> by Sharon Glotzer’s group, clumps of
			granular particles, lipid molecules consiting of one or more point
			dipoles connected to other spheroids or ellipsoids, irregular
			particles built from line segments (2d) or triangles (3d), and
			coarse-grain models of nano or colloidal particles consisting of a
			small number of constituent particles. Note that the <a class="reference internal" href="fix_shake.html"><span class="doc">fix shake</span></a> command can also be used to rigidify small
			molecules of 2, 3, or 4 atoms, e.g. water molecules. That fix treats
			the constituent atoms as point masses.</p>
			<p>These fixes also update the positions and velocities of the atoms in
			each rigid body via time integration, in the NVE, NVT, NPT, or NPH
			ensemble, as described below.</p>
			<p>There are two main variants of this fix, fix rigid and fix
			rigid/small. The NVE/NVT/NPT/NHT versions belong to one of the two
			variants, as their style names indicate.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">Not all of the <em>bodystyle</em> options and keyword/value options are
			available for both the <em>rigid</em> and <em>rigid/small</em> variants. See
			details below.</p>
			</div>
			<p>The <em>rigid</em> styles are typically the best choice for a system with a
			small number of large rigid bodies, each of which can extend across
			the domain of many processors. It operates by creating a single
			global list of rigid bodies, which all processors contribute to.
			MPI_Allreduce operations are performed each timestep to sum the
			contributions from each processor to the force and torque on all the
			bodies. This operation will not scale well in parallel if large
			numbers of rigid bodies are simulated.</p>
			<p>The <em>rigid/small</em> styles are typically best for a system with a large
			number of small rigid bodies. Each body is assigned to the atom
			closest to the geometrical center of the body. The fix operates using
			local lists of rigid bodies owned by each processor and information is
			exchanged and summed via local communication between neighboring
			processors when ghost atom info is accumlated.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">To use the <em>rigid/small</em> styles the ghost atom cutoff must be
			large enough to span the distance between the atom that owns the body
			and every other atom in the body. This distance value is printed out
			when the rigid bodies are defined. If the
			<a class="reference internal" href="pair_style.html"><span class="doc">pair_style</span></a> cutoff plus neighbor skin does not span
			this distance, then you should use the <a class="reference internal" href="comm_modify.html"><span class="doc">comm_modify cutoff</span></a> command with a setting epsilon larger than
			the distance.</p>
			</div>
			<p>Which of the two variants is faster for a particular problem is hard
			to predict. The best way to decide is to perform a short test run.
			Both variants should give identical numerical answers for short runs.
			Long runs should give statistically similar results, but round-off
			differences may accumulate to produce divergent trajectories.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">You should not update the atoms in rigid bodies via other
			time-integration fixes (e.g. <a class="reference internal" href="fix_nve.html"><span class="doc">fix nve</span></a>, <a class="reference internal" href="fix_nh.html"><span class="doc">fix nvt</span></a>, <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a>), or you will be integrating
			their motion more than once each timestep. When performing a hybrid
			simulation with some atoms in rigid bodies, and some not, a separate
			time integration fix like <a class="reference internal" href="fix_nve.html"><span class="doc">fix nve</span></a> or <a class="reference internal" href="fix_nh.html"><span class="doc">fix nvt</span></a> should be used for the non-rigid particles.</p>
			</div>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">These fixes are overkill if you simply want to hold a collection
			of atoms stationary or have them move with a constant velocity. A
			simpler way to hold atoms stationary is to not include those atoms in
			your time integration fix. E.g. use “fix 1 mobile nve” instead of
			“fix 1 all nve”, where “mobile” is the group of atoms that you want to
			move. You can move atoms with a constant velocity by assigning them
			an initial velocity (via the <a class="reference internal" href="velocity.html"><span class="doc">velocity</span></a> command),
			setting the force on them to 0.0 (via the <a class="reference internal" href="fix_setforce.html"><span class="doc">fix setforce</span></a> command), and integrating them as usual
			(e.g. via the <a class="reference internal" href="fix_nve.html"><span class="doc">fix nve</span></a> command).</p>
			</div>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">The aggregate properties of each rigid body are calculated one
			time at the start of the first simulation run after these fixes are
			specified. The properties include the position and velocity of the
			center-of-mass of the body, its moments of inertia, and its angular
			momentum. This is done using the properties of the constituent atoms
			of the body at that point in time (or see the <em>infile</em> keyword
			option). Thereafter, changing properties of individual atoms in the
			body will have no effect on a rigid body’s dynamics, unless they
			affect the <a class="reference internal" href="pair_style.html"><span class="doc">pair_style</span></a> interactions that individual
			particles are part of. For example, you might think you could
			displace the atoms in a body or add a large velocity to each atom in a
			body to make it move in a desired direction before a 2nd run is
			performed, using the <a class="reference internal" href="set.html"><span class="doc">set</span></a> or
			<a class="reference internal" href="displace_atoms.html"><span class="doc">displace_atoms</span></a> or <a class="reference internal" href="velocity.html"><span class="doc">velocity</span></a>
			command. But these commands will not affect the internal attributes
			of the body, and the position and velocity of individual atoms in the
			body will be reset when time integration starts.</p>
			</div>
			<hr class="docutils" />
			<p>Each rigid body must have two or more atoms. An atom can belong to at
			most one rigid body. Which atoms are in which bodies can be defined
			via several options.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">With the <em>rigid/small</em> styles, which require that <em>bodystyle</em> be
			specified as <em>molecule</em>, you can define a system that has no rigid
			bodies initially. This is useful when you are using the <em>mol</em> keyword
			in conjunction with another fix that is adding rigid bodies on-the-fly
			as molecules, such as <a class="reference internal" href="fix_deposit.html"><span class="doc">fix deposit</span></a> or <a class="reference internal" href="fix_pour.html"><span class="doc">fix pour</span></a>.</p>
			</div>
			<p>For bodystyle <em>single</em> the entire fix group of atoms is treated as one
			rigid body. This option is only allowed for the <em>rigid</em> styles.</p>
			<p>For bodystyle <em>molecule</em>, each set of atoms in the fix group with a
			different molecule ID is treated as a rigid body. This option is
			allowed for both the <em>rigid</em> and <em>rigid/small</em> styles. Note that
			atoms with a molecule ID = 0 will be treated as a single rigid body.
			For a system with atomic solvent (typically this is atoms with
			molecule ID = 0) surrounding rigid bodies, this may not be what you
			want. Thus you should be careful to use a fix group that only
			includes atoms you want to be part of rigid bodies.</p>
			<p>For bodystyle <em>group</em>, each of the listed groups is treated as a
			separate rigid body. Only atoms that are also in the fix group are
			included in each rigid body. This option is only allowed for the
			<em>rigid</em> styles.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">To compute the initial center-of-mass position and other
			properties of each rigid body, the image flags for each atom in the
			body are used to “unwrap” the atom coordinates. Thus you must insure
			that these image flags are consistent so that the unwrapping creates a
			valid rigid body (one where the atoms are close together),
			particularly if the atoms in a single rigid body straddle a periodic
			boundary. This means the input data file or restart file must define
			the image flags for each atom consistently or that you have used the
			<a class="reference internal" href="set.html"><span class="doc">set</span></a> command to specify them correctly. If a dimension is
			non-periodic then the image flag of each atom must be 0 in that
			dimension, else an error is generated.</p>
			</div>
			<p>The <em>force</em> and <em>torque</em> keywords discussed next are only allowed for
			the <em>rigid</em> styles.</p>
			<p>By default, each rigid body is acted on by other atoms which induce an
			external force and torque on its center of mass, causing it to
			translate and rotate. Components of the external center-of-mass force
			and torque can be turned off by the <em>force</em> and <em>torque</em> keywords.
			This may be useful if you wish a body to rotate but not translate, or
			vice versa, or if you wish it to rotate or translate continuously
			unaffected by interactions with other particles. Note that if you
			expect a rigid body not to move or rotate by using these keywords, you
			must insure its initial center-of-mass translational or angular
			velocity is 0.0. Otherwise the initial translational or angular
			momentum the body has will persist.</p>
			<p>An xflag, yflag, or zflag set to <em>off</em> means turn off the component of
			force of torque in that dimension. A setting of <em>on</em> means turn on
			the component, which is the default. Which rigid body(s) the settings
			apply to is determined by the first argument of the <em>force</em> and
			<em>torque</em> keywords. It can be an integer M from 1 to Nbody, where
			Nbody is the number of rigid bodies defined. A wild-card asterisk can
			be used in place of, or in conjunction with, the M argument to set the
			flags for multiple rigid bodies. This takes the form “” or “n” or
			“n” or “mn”. If N = the number of rigid bodies, then an asterisk
			with no numeric values means all bodies from 1 to N. A leading
			asterisk means all bodies from 1 to n (inclusive). A trailing
			asterisk means all bodies from n to N (inclusive). A middle asterisk
			means all types from m to n (inclusive). Note that you can use the
			<em>force</em> or <em>torque</em> keywords as many times as you like. If a
			particular rigid body has its component flags set multiple times, the
			settings from the final keyword are used.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">For computational efficiency, you may wish to turn off pairwise
			and bond interactions within each rigid body, as they no longer
			contribute to the motion. The <a class="reference internal" href="neigh_modify.html"><span class="doc">neigh_modify exclude</span></a> and <a class="reference internal" href="delete_bonds.html"><span class="doc">delete_bonds</span></a>
			commands are used to do this. If the rigid bodies have strongly
			overalapping atoms, you may need to turn off these interactions to
			avoid numerical problems due to large equal/opposite intra-body forces
			swamping the contribution of small inter-body forces.</p>
			</div>
			<p>For computational efficiency, you should typically define one fix
			rigid or fix rigid/small command which includes all the desired rigid
			bodies. LAMMPS will allow multiple rigid fixes to be defined, but it
			is more expensive.</p>
			<hr class="docutils" />
			<p>The constituent particles within a rigid body can be point particles
			(the default in LAMMPS) or finite-size particles, such as spheres or
			ellipsoids or line segments or triangles. See the <a class="reference internal" href="atom_style.html"><span class="doc">atom_style sphere and ellipsoid and line and tri</span></a> commands for more
			details on these kinds of particles. Finite-size particles contribute
			differently to the moment of inertia of a rigid body than do point
			particles. Finite-size particles can also experience torque (e.g. due
			to <a class="reference internal" href="pair_gran.html"><span class="doc">frictional granular interactions</span></a>) and have an
			orientation. These contributions are accounted for by these fixes.</p>
			<p>Forces between particles within a body do not contribute to the
			external force or torque on the body. Thus for computational
			efficiency, you may wish to turn off pairwise and bond interactions
			between particles within each rigid body. The <a class="reference internal" href="neigh_modify.html"><span class="doc">neigh_modify exclude</span></a> and <a class="reference internal" href="delete_bonds.html"><span class="doc">delete_bonds</span></a>
			commands are used to do this. For finite-size particles this also
			means the particles can be highly overlapped when creating the rigid
			body.</p>
			<hr class="docutils" />
			<p>The <em>rigid</em>, <em>rigid/nve</em>, <em>rigid/small</em>, and <em>rigid/small/nve</em> styles
			perform constant NVE time integration. They are referred to below as
			the 4 NVE rigid styles. The only difference is that the <em>rigid</em> and
			<em>rigid/small</em> styles use an integration technique based on Richardson
			iterations. The <em>rigid/nve</em> and <em>rigid/small/nve</em> styles uses the
			methods described in the paper by <a class="reference internal" href="#miller"><span class="std std-ref">Miller</span></a>, which are thought
			to provide better energy conservation than an iterative approach.</p>
			<p>The <em>rigid/nvt</em> and <em>rigid/nvt/small</em> styles performs constant NVT
			integration using a Nose/Hoover thermostat with chains as described
			originally in <a class="reference internal" href="#hoover"><span class="std std-ref">(Hoover)</span></a> and <a class="reference internal" href="#martyna"><span class="std std-ref">(Martyna)</span></a>, which
			thermostats both the translational and rotational degrees of freedom
			of the rigid bodies. They are referred to below as the 2 NVT rigid
			styles. The rigid-body algorithm used by <em>rigid/nvt</em> is described in
			the paper by <a class="reference internal" href="#kamberaj"><span class="std std-ref">Kamberaj</span></a>.</p>
			<p>The <em>rigid/npt</em>, <em>rigid/nph</em>, <em>rigid/npt/small</em>, and <em>rigid/nph/small</em>
			styles perform constant NPT or NPH integration using a Nose/Hoover
			barostat with chains. They are referred to below as the 4 NPT and NPH
			rigid styles. For the NPT case, the same Nose/Hoover thermostat is
			also used as with <em>rigid/nvt</em> and <em>rigid/nvt/small</em>.</p>
			<p>The barostat parameters are specified using one or more of the <em>iso</em>,
			<em>aniso</em>, <em>x</em>, <em>y</em>, <em>z</em> and <em>couple</em> keywords. These keywords give you
			the ability to specify 3 diagonal components of the external stress
			tensor, and to couple these components together so that the dimensions
			they represent are varied together during a constant-pressure
			simulation. The effects of these keywords are similar to those
			defined in <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt/nph</span></a></p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">Currently the <em>rigid/npt</em>, <em>rigid/nph</em>, <em>rigid/npt/small</em>, and
			<em>rigid/nph/small</em> styles do not support triclinic (non-orthongonal)
			boxes.</p>
			</div>
			<p>The target pressures for each of the 6 components of the stress tensor
			can be specified independently via the <em>x</em>, <em>y</em>, <em>z</em> keywords, which
			correspond to the 3 simulation box dimensions. For each component,
			the external pressure or tensor component at each timestep is a ramped
			value during the run from <em>Pstart</em> to <em>Pstop</em>. If a target pressure is
			specified for a component, then the corresponding box dimension will
			change during a simulation. For example, if the <em>y</em> keyword is used,
			the y-box length will change. A box dimension will not change if that
			component is not specified, although you have the option to change
			that dimension via the <a class="reference internal" href="fix_deform.html"><span class="doc">fix deform</span></a> command.</p>
			<p>For all barostat keywords, the <em>Pdamp</em> parameter operates like the
			<em>Tdamp</em> parameter, determining the time scale on which pressure is
			relaxed. For example, a value of 10.0 means to relax the pressure in
			a timespan of (roughly) 10 time units (e.g. tau or fmsec or psec - see
			the <a class="reference internal" href="units.html"><span class="doc">units</span></a> command).</p>
			<p>Regardless of what atoms are in the fix group (the only atoms which
			are time integrated), a global pressure or stress tensor is computed
			for all atoms. Similarly, when the size of the simulation box is
			changed, all atoms are re-scaled to new positions, unless the keyword
			<em>dilate</em> is specified with a <em>dilate-group-ID</em> for a group that
			represents a subset of the atoms. This can be useful, for example, to
			leave the coordinates of atoms in a solid substrate unchanged and
			controlling the pressure of a surrounding fluid. Another example is a
			system consisting of rigid bodies and point particles where the
			barostat is only coupled with the rigid bodies. This option should be
			used with care, since it can be unphysical to dilate some atoms and
			not others, because it can introduce large, instantaneous
			displacements between a pair of atoms (one dilated, one not) that are
			far from the dilation origin.</p>
			<p>The <em>couple</em> keyword allows two or three of the diagonal components of
			the pressure tensor to be “coupled” together. The value specified
			with the keyword determines which are coupled. For example, <em>xz</em>
			means the <em>Pxx</em> and <em>Pzz</em> components of the stress tensor are coupled.
			<em>Xyz</em> means all 3 diagonal components are coupled. Coupling means two
			things: the instantaneous stress will be computed as an average of the
			corresponding diagonal components, and the coupled box dimensions will
			be changed together in lockstep, meaning coupled dimensions will be
			dilated or contracted by the same percentage every timestep. The
			<em>Pstart</em>, <em>Pstop</em>, <em>Pdamp</em> parameters for any coupled dimensions must
			be identical. <em>Couple xyz</em> can be used for a 2d simulation; the <em>z</em>
			dimension is simply ignored.</p>
			<p>The <em>iso</em> and <em>aniso</em> keywords are simply shortcuts that are
			equivalent to specifying several other keywords together.</p>
			<p>The keyword <em>iso</em> means couple all 3 diagonal components together when
			pressure is computed (hydrostatic pressure), and dilate/contract the
			dimensions together. Using “iso Pstart Pstop Pdamp” is the same as
			specifying these 4 keywords:</p>
			<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">x</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">y</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">z</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">couple</span> <span class="n">xyz</span>
			</pre></div>
			</div>
			<p>The keyword <em>aniso</em> means <em>x</em>, <em>y</em>, and <em>z</em> dimensions are controlled
			independently using the <em>Pxx</em>, <em>Pyy</em>, and <em>Pzz</em> components of the
			stress tensor as the driving forces, and the specified scalar external
			pressure. Using “aniso Pstart Pstop Pdamp” is the same as specifying
			these 4 keywords:</p>
			<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">x</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">y</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">z</span> <span class="n">Pstart</span> <span class="n">Pstop</span> <span class="n">Pdamp</span>
			<span class="n">couple</span> <span class="n">none</span>
			</pre></div>
			</div>
			<hr class="docutils" />
			<p>The keyword/value option pairs are used in the following ways.</p>
			<p>The <em>langevin</em> and <em>temp</em> and <em>tparam</em> keywords perform thermostatting
			of the rigid bodies, altering both their translational and rotational
			degrees of freedom. What is meant by “temperature” of a collection of
			rigid bodies and how it can be monitored via the fix output is
			discussed below.</p>
			<p>The <em>langevin</em> keyword applies a Langevin thermostat to the constant
			NVE time integration performed by any of the 4 NVE rigid styles:
			<em>rigid</em>, <em>rigid/nve</em>, <em>rigid/small</em>, <em>rigid/small/nve</em>. It cannot be
			used with the 2 NVT rigid styles: <em>rigid/nvt</em>, <em>rigid/small/nvt</em>. The
			desired temperature at each timestep is a ramped value during the run
			from <em>Tstart</em> to <em>Tstop</em>. The <em>Tdamp</em> parameter is specified in time
			units and determines how rapidly the temperature is relaxed. For
			example, a value of 100.0 means to relax the temperature in a timespan
			of (roughly) 100 time units (tau or fmsec or psec - see the
			<a class="reference internal" href="units.html"><span class="doc">units</span></a> command). The random # <em>seed</em> must be a positive
			integer.</p>
			<p>The way that Langevin thermostatting operates is explained on the <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a> doc page. If you wish to simply viscously
			damp the rotational motion without thermostatting, you can set
			<em>Tstart</em> and <em>Tstop</em> to 0.0, which means only the viscous drag term in
			the Langevin thermostat will be applied. See the discussion on the
			<a class="reference internal" href="fix_viscous.html"><span class="doc">fix viscous</span></a> doc page for details.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">When the <em>langevin</em> keyword is used with fix rigid versus fix
			rigid/small, different dynamics will result for parallel runs. This
			is because of the way random numbers are used in the two cases. The
			dynamics for the two cases should be statistically similar, but will
			not be identical, even for a single timestep.</p>
			</div>
			<p>The <em>temp</em> and <em>tparam</em> keywords apply a Nose/Hoover thermostat to the
			NVT time integration performed by the 2 NVT rigid styles. They cannot
			be used with the 4 NVE rigid styles. The desired temperature at each
			timestep is a ramped value during the run from <em>Tstart</em> to <em>Tstop</em>.
			The <em>Tdamp</em> parameter is specified in time units and determines how
			rapidly the temperature is relaxed. For example, a value of 100.0
			means to relax the temperature in a timespan of (roughly) 100 time
			units (tau or fmsec or psec - see the <a class="reference internal" href="units.html"><span class="doc">units</span></a> command).</p>
			<p>Nose/Hoover chains are used in conjunction with this thermostat. The
			<em>tparam</em> keyword can optionally be used to change the chain settings
			used. <em>Tchain</em> is the number of thermostats in the Nose Hoover chain.
			This value, along with <em>Tdamp</em> can be varied to dampen undesirable
			oscillations in temperature that can occur in a simulation. As a rule
			of thumb, increasing the chain length should lead to smaller
			oscillations. The keyword <em>pchain</em> specifies the number of
			thermostats in the chain thermostatting the barostat degrees of
			freedom.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">There are alternate ways to thermostat a system of rigid bodies.
			You can use <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a> to treat the individual
			particles in the rigid bodies as effectively immersed in an implicit
			solvent, e.g. a Brownian dynamics model. For hybrid systems with both
			rigid bodies and solvent particles, you can thermostat only the
			solvent particles that surround one or more rigid bodies by
			appropriate choice of groups in the compute and fix commands for
			temperature and thermostatting. The solvent interactions with the
			rigid bodies should then effectively thermostat the rigid body
			temperature as well without use of the Langevin or Nose/Hoover options
			associated with the fix rigid commands.</p>
			</div>
			<hr class="docutils" />
			<p>The <em>mol</em> keyword can only be used with the <em>rigid/small</em> styles. It
			must be used when other commands, such as <a class="reference internal" href="fix_deposit.html"><span class="doc">fix deposit</span></a> or <a class="reference internal" href="fix_pour.html"><span class="doc">fix pour</span></a>, add rigid
			bodies on-the-fly during a simulation. You specify a <em>template-ID</em>
			previously defined using the <a class="reference internal" href="molecule.html"><span class="doc">molecule</span></a> command, which
			reads a file that defines the molecule. You must use the same
			<em>template-ID</em> that the other fix which is adding rigid bodies uses.
			The coordinates, atom types, atom diameters, center-of-mass, and
			moments of inertia can be specified in the molecule file. See the
			<a class="reference internal" href="molecule.html"><span class="doc">molecule</span></a> command for details. The only settings
			required to be in this file are the coordinates and types of atoms in
			the molecule, in which case the molecule command calculates the other
			quantities itself.</p>
			<p>Note that these other fixes create new rigid bodies, in addition to
			those defined initially by this fix via the <em>bodystyle</em> setting.</p>
			<p>Also note that when using the <em>mol</em> keyword, extra restart information
			about all rigid bodies is written out whenever a restart file is
			written out. See the NOTE in the next section for details.</p>
			<hr class="docutils" />
			<p>The <em>infile</em> keyword allows a file of rigid body attributes to be read
			in from a file, rather then having LAMMPS compute them. There are 5
			such attributes: the total mass of the rigid body, its center-of-mass
			position, its 6 moments of inertia, its center-of-mass velocity, and
			the 3 image flags of the center-of-mass position. For rigid bodies
			consisting of point particles or non-overlapping finite-size
			particles, LAMMPS can compute these values accurately. However, for
			rigid bodies consisting of finite-size particles which overlap each
			other, LAMMPS will ignore the overlaps when computing these 4
			attributes. The amount of error this induces depends on the amount of
			overlap. To avoid this issue, the values can be pre-computed
			(e.g. using Monte Carlo integration).</p>
			<p>The format of the file is as follows. Note that the file does not
			have to list attributes for every rigid body integrated by fix rigid.
			Only bodies which the file specifies will have their computed
			attributes overridden. The file can contain initial blank lines or
			comment lines starting with “#” which are ignored. The first
			non-blank, non-comment line should list N = the number of lines to
			follow. The N successive lines contain the following information:</p>
			<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">ID1</span> <span class="n">masstotal</span> <span class="n">xcm</span> <span class="n">ycm</span> <span class="n">zcm</span> <span class="n">ixx</span> <span class="n">iyy</span> <span class="n">izz</span> <span class="n">ixy</span> <span class="n">ixz</span> <span class="n">iyz</span> <span class="n">vxcm</span> <span class="n">vycm</span> <span class="n">vzcm</span> <span class="n">lx</span> <span class="n">ly</span> <span class="n">lz</span> <span class="n">ixcm</span> <span class="n">iycm</span> <span class="n">izcm</span>
			<span class="n">ID2</span> <span class="n">masstotal</span> <span class="n">xcm</span> <span class="n">ycm</span> <span class="n">zcm</span> <span class="n">ixx</span> <span class="n">iyy</span> <span class="n">izz</span> <span class="n">ixy</span> <span class="n">ixz</span> <span class="n">iyz</span> <span class="n">vxcm</span> <span class="n">vycm</span> <span class="n">vzcm</span> <span class="n">lx</span> <span class="n">ly</span> <span class="n">lz</span> <span class="n">ixcm</span> <span class="n">iycm</span> <span class="n">izcm</span>
			<span class="o">...</span>
			<span class="n">IDN</span> <span class="n">masstotal</span> <span class="n">xcm</span> <span class="n">ycm</span> <span class="n">zcm</span> <span class="n">ixx</span> <span class="n">iyy</span> <span class="n">izz</span> <span class="n">ixy</span> <span class="n">ixz</span> <span class="n">iyz</span> <span class="n">vxcm</span> <span class="n">vycm</span> <span class="n">vzcm</span> <span class="n">lx</span> <span class="n">ly</span> <span class="n">lz</span> <span class="n">ixcm</span> <span class="n">iycm</span> <span class="n">izcm</span>
			</pre></div>
			</div>
			<p>The rigid body IDs are all positive integers. For the <em>single</em>
			bodystyle, only an ID of 1 can be used. For the <em>group</em> bodystyle,
			IDs from 1 to Ng can be used where Ng is the number of specified
			groups. For the <em>molecule</em> bodystyle, use the molecule ID for the
			atoms in a specific rigid body as the rigid body ID.</p>
			<p>The masstotal and center-of-mass coordinates (xcm,ycm,zcm) are
			self-explanatory. The center-of-mass should be consistent with what
			is calculated for the position of the rigid body with all its atoms
			unwrapped by their respective image flags. If this produces a
			center-of-mass that is outside the simulation box, LAMMPS wraps it
			back into the box.</p>
			<p>The 6 moments of inertia (ixx,iyy,izz,ixy,ixz,iyz) should be the
			values consistent with the current orientation of the rigid body
			around its center of mass. The values are with respect to the
			simulation box XYZ axes, not with respect to the prinicpal axes of the
			rigid body itself. LAMMPS performs the latter calculation internally.</p>
			<p>The (vxcm,vycm,vzcm) values are the velocity of the center of mass.
			The (lx,ly,lz) values are the angular momentum of the body. The
			(vxcm,vycm,vzcm) and (lx,ly,lz) values can simply be set to 0 if you
			wish the body to have no initial motion.</p>
			<p>The (ixcm,iycm,izcm) values are the image flags of the center of mass
			of the body. For periodic dimensions, they specify which image of the
			simulation box the body is considered to be in. An image of 0 means
			it is inside the box as defined. A value of 2 means add 2 box lengths
			to get the true value. A value of -1 means subtract 1 box length to
			get the true value. LAMMPS updates these flags as the rigid bodies
			cross periodic boundaries during the simulation.</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">If you use the <em>infile</em> or <em>mol</em> keywords and write restart
			files during a simulation, then each time a restart file is written,
			the fix also write an auxiliary restart file with the name
			rfile.rigid, where “rfile” is the name of the restart file,
			e.g. tmp.restart.10000 and tmp.restart.10000.rigid. This auxiliary
			file is in the same format described above. Thus it can be used in a
			new input script that restarts the run and re-specifies a rigid fix
			using an <em>infile</em> keyword and the appropriate filename. Note that the
			auxiliary file will contain one line for every rigid body, even if the
			original file only listed a subset of the rigid bodies.</p>
			</div>
			<hr class="docutils" />
			<p>If you use a <a class="reference internal" href="compute.html"><span class="doc">temperature compute</span></a> with a group that
			includes particles in rigid bodies, the degrees-of-freedom removed by
			each rigid body are accounted for in the temperature (and pressure)
			computation, but only if the temperature group includes all the
			particles in a particular rigid body.</p>
			<p>A 3d rigid body has 6 degrees of freedom (3 translational, 3
			rotational), except for a collection of point particles lying on a
			straight line, which has only 5, e.g a dimer. A 2d rigid body has 3
			degrees of freedom (2 translational, 1 rotational).</p>
			<div class="admonition note">
			<p class="first admonition-title">Note</p>
			<p class="last">You may wish to explicitly subtract additional
			degrees-of-freedom if you use the <em>force</em> and <em>torque</em> keywords to
			eliminate certain motions of one or more rigid bodies. LAMMPS does
			not do this automatically.</p>
			</div>
			<p>The rigid body contribution to the pressure of the system (virial) is
			also accounted for by this fix.</p>
			<hr class="docutils" />
			<p>If your simlulation is a hybrid model with a mixture of rigid bodies
			and non-rigid particles (e.g. solvent) there are several ways these
			rigid fixes can be used in tandem with <a class="reference internal" href="fix_nve.html"><span class="doc">fix nve</span></a>, <a class="reference internal" href="fix_nh.html"><span class="doc">fix nvt</span></a>, <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a>, and <a class="reference internal" href="fix_nh.html"><span class="doc">fix nph</span></a>.</p>
			<p>If you wish to perform NVE dynamics (no thermostatting or
			barostatting), use one of 4 NVE rigid styles to integrate the rigid
			bodies, and <a class="reference internal" href="fix_nve.html"><span class="doc">fix nve</span></a> to integrate the non-rigid
			particles.</p>
			<p>If you wish to perform NVT dynamics (thermostatting, but no
			barostatting), you can use one of the 2 NVT rigid styles for the rigid
			bodies, and any thermostatting fix for the non-rigid particles (<a class="reference internal" href="fix_nh.html"><span class="doc">fix nvt</span></a>, <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a>, <a class="reference internal" href="fix_temp_berendsen.html"><span class="doc">fix temp/berendsen</span></a>). You can also use one of the
			4 NVE rigid styles for the rigid bodies and thermostat them using <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a> on the group that contains all the
			particles in the rigid bodies. The net force added by <a class="reference internal" href="fix_langevin.html"><span class="doc">fix langevin</span></a> to each rigid body effectively thermostats
			its translational center-of-mass motion. Not sure how well it does at
			thermostatting its rotational motion.</p>
			<p>If you with to perform NPT or NPH dynamics (barostatting), you cannot
			use both <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a> and the NPT or NPH rigid styles. This
			is because there can only be one fix which monitors the global
			pressure and changes the simulation box dimensions. So you have 3
			choices:</p>
			<ul class="simple">
			<li>Use one of the 4 NPT or NPH styles for the rigid bodies. Use the
			<em>dilate</em> all option so that it will dilate the positions of the
			non-rigid particles as well. Use <a class="reference internal" href="fix_nh.html"><span class="doc">fix nvt</span></a> (or any other
			thermostat) for the non-rigid particles.</li>
			<li>Use <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a> for the group of non-rigid particles. Use
			the <em>dilate</em> all option so that it will dilate the center-of-mass
			positions of the rigid bodies as well. Use one of the 4 NVE or 2 NVT
			rigid styles for the rigid bodies.</li>
			<li>Use <a class="reference internal" href="fix_press_berendsen.html"><span class="doc">fix press/berendsen</span></a> to compute the
			pressure and change the box dimensions. Use one of the 4 NVE or 2 NVT
			rigid styles for the rigid bodies. Use <a class="reference external" href="fix_nh.thml">fix nvt</a> (or any
			other thermostat) for the non-rigid particles.</li>
			</ul>
			<p>In all case, the rigid bodies and non-rigid particles both contribute
			to the global pressure and the box is scaled the same by any of the
			barostatting fixes.</p>
			<p>You could even use the 2nd and 3rd options for a non-hybrid simulation
			consisting of only rigid bodies, assuming you give <a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a> an empty group, though it’s an odd thing to do. The
			barostatting fixes (<a class="reference internal" href="fix_nh.html"><span class="doc">fix npt</span></a> and <a class="reference internal" href="fix_press_berendsen.html"><span class="doc">fix press/berensen</span></a>) will monitor the pressure
			and change the box dimensions, but not time integrate any particles.
			The integration of the rigid bodies will be performed by fix
			rigid/nvt.</p>
			<hr class="docutils" />
			<p>Styles with a <em>gpu</em>, <em>intel</em>, <em>kk</em>, <em>omp</em>, or <em>opt</em> suffix are
			functionally the same as the corresponding style without the suffix.
			They have been optimized to run faster, depending on your available
			hardware, as discussed in <a class="reference internal" href="Section_accelerate.html"><span class="doc">Section 5</span></a>
			of the manual. The accelerated styles take the same arguments and
			should produce the same results, except for round-off and precision
			issues.</p>
			<p>These accelerated styles are part of the GPU, USER-INTEL, KOKKOS,
			USER-OMP and OPT packages, respectively. They are only enabled if
			LAMMPS was built with those packages. See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a> section for more info.</p>
			<p>You can specify the accelerated styles explicitly in your input script
			by including their suffix, or you can use the <a class="reference internal" href="Section_start.html#start-7"><span class="std std-ref">-suffix command-line switch</span></a> when you invoke LAMMPS, or you can
			use the <a class="reference internal" href="suffix.html"><span class="doc">suffix</span></a> command in your input script.</p>
			<p>See <a class="reference internal" href="Section_accelerate.html"><span class="doc">Section 5</span></a> of the manual for
			more instructions on how to use the accelerated styles effectively.</p>
			<hr class="docutils" />
			<p><strong>Restart, fix_modify, output, run start/stop, minimize info:</strong></p>
			<p>No information about the 4 NVE rigid styles is written to <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>. The exception is if the <em>infile</em> or
			<em>mol</em> keyword is used, in which case an auxiliary file is written out
			with rigid body information each time a restart file is written, as
			explained above for the <em>infile</em> keyword. For the 2 NVT rigid styles,
			the state of the Nose/Hoover thermostat is written to <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>. Ditto for the 4 NPT and NPH rigid styles, and
			the state of the Nose/Hoover barostat. See the
			<a class="reference internal" href="read_restart.html"><span class="doc">read_restart</span></a> command for info on how to re-specify
			a fix in an input script that reads a restart file, so that the
			operation of the fix continues in an uninterrupted fashion.</p>
			<p>The <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>energy</em> option is supported by the 6
			NVT, NPT, NPH rigid styles to add the energy change induced by the
			thermostatting to the system’s potential energy as part of
			<a class="reference internal" href="thermo_style.html"><span class="doc">thermodynamic output</span></a>.</p>
			<p>The <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>temp</em> and <em>press</em> options are
			supported by the 4 NPT and NPH rigid styles to change the computes
			used to calculate the instantaneous pressure tensor. Note that the 2
			NVT rigid fixes do not use any external compute to compute
			instantaneous temperature.</p>
			<p>The 2 NVE rigid fixes compute a global scalar which can be accessed by
			various <a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">output commands</span></a>. The scalar
			value calculated by these fixes is “intensive”. The scalar is the
			current temperature of the collection of rigid bodies. This is
			averaged over all rigid bodies and their translational and rotational
			degrees of freedom. The translational energy of a rigid body is 1/2 m
			v^2, where m = total mass of the body and v = the velocity of its
			center of mass. The rotational energy of a rigid body is 1/2 I w^2,
			where I = the moment of inertia tensor of the body and w = its angular
			velocity. Degrees of freedom constrained by the <em>force</em> and <em>torque</em>
			keywords are removed from this calculation, but only for the <em>rigid</em>
			and <em>rigid/nve</em> fixes.</p>
			<p>The 6 NVT, NPT, NPH rigid fixes compute a global scalar which can be
			accessed by various <a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">output commands</span></a>.
			The scalar value calculated by these fixes is “extensive”. The scalar
			is the cumulative energy change due to the thermostatting and
			barostatting the fix performs.</p>
			<p>All of the <em>rigid</em> styles (not the <em>rigid/small</em> styles) compute a
			global array of values which can be accessed by various <a class="reference internal" href="Section_howto.html#howto-15"><span class="std std-ref">output commands</span></a>. Similar information about the
			bodies defined by the <em>rigid/small</em> styles can be accessed via the
			<a class="reference internal" href="compute_rigid_local.html"><span class="doc">compute rigid/local</span></a> command.</p>
			<p>The number of rows in the array is equal to the number of rigid
			bodies. The number of columns is 15. Thus for each rigid body, 15
			values are stored: the xyz coords of the center of mass (COM), the xyz
			components of the COM velocity, the xyz components of the force acting
			on the COM, the xyz components of the torque acting on the COM, and
			the xyz image flags of the COM.</p>
			<p>The center of mass (COM) for each body is similar to unwrapped
			coordinates written to a dump file. It will always be inside (or
			slightly outside) the simulation box. The image flags have the same
			meaning as image flags for atom positions (see the “dump” command).
			This means you can calculate the unwrapped COM by applying the image
			flags to the COM, the same as when unwrapped coordinates are written
			to a dump file.</p>
			<p>The force and torque values in the array are not affected by the
			<em>force</em> and <em>torque</em> keywords in the fix rigid command; they reflect
			values before any changes are made by those keywords.</p>
			<p>The ordering of the rigid bodies (by row in the array) is as follows.
			For the <em>single</em> keyword there is just one rigid body. For the
			<em>molecule</em> keyword, the bodies are ordered by ascending molecule ID.
			For the <em>group</em> keyword, the list of group IDs determines the ordering
			of bodies.</p>
			<p>The array values calculated by these fixes are “intensive”, meaning
			they are independent of the number of atoms in the simulation.</p>
			<p>No parameter of these fixes can be used with the <em>start/stop</em> keywords
			of the <a class="reference internal" href="run.html"><span class="doc">run</span></a> command. These fixes are not invoked during
			<a class="reference internal" href="minimize.html"><span class="doc">energy minimization</span></a>.</p>
			</div>
			<hr class="docutils" />
			<div class="section" id="restrictions">
			<h2>Restrictions</h2>
			<p>These fixes are all part of the RIGID package. It is only enabled if
			LAMMPS was built with that package. See the <a class="reference internal" href="Section_start.html#start-3"><span class="std std-ref">Making LAMMPS</span></a> section for more info.</p>
			<p>Assigning a temperature via the <a class="reference internal" href="velocity.html"><span class="doc">velocity create</span></a>
			command to a system with <a class="reference internal" href="#"><span class="doc">rigid bodies</span></a> may not have
			the desired outcome for two reasons. First, the velocity command can
			be invoked before the rigid-body fix is invoked or initialized and the
			number of adjusted degrees of freedom (DOFs) is known. Thus it is not
			possible to compute the target temperature correctly. Second, the
			assigned velocities may be partially canceled when constraints are
			first enforced, leading to a different temperature than desired. A
			workaround for this is to perform a <a class="reference internal" href="run.html"><span class="doc">run 0</span></a> command, which
			insures all DOFs are accounted for properly, and then rescale the
			temperature to the desired value before performing a simulation. For
			example:</p>
			<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">velocity</span> <span class="nb">all</span> <span class="n">create</span> <span class="mf">300.0</span> <span class="mi">12345</span>
			<span class="n">run</span> <span class="mi">0</span> <span class="c1"># temperature may not be 300K</span>
			<span class="n">velocity</span> <span class="nb">all</span> <span class="n">scale</span> <span class="mf">300.0</span> <span class="c1"># now it should be</span>
			</pre></div>
			</div>
			</div>
			<div class="section" id="related-commands">
			<h2>Related commands</h2>
			<p><a class="reference internal" href="delete_bonds.html"><span class="doc">delete_bonds</span></a>, <a class="reference internal" href="neigh_modify.html"><span class="doc">neigh_modify</span></a>
			exclude, <a class="reference internal" href="fix_shake.html"><span class="doc">fix shake</span></a></p>
			</div>
			<div class="section" id="default">
			<h2>Default</h2>
			<p>The option defaults are force * on on on and torque * on on on,
			meaning all rigid bodies are acted on by center-of-mass force and
			torque. Also Tchain = Pchain = 10, Titer = 1, Torder = 3.</p>
			<hr class="docutils" />
			<p id="hoover"><strong>(Hoover)</strong> Hoover, Phys Rev A, 31, 1695 (1985).</p>
			<p id="kamberaj"><strong>(Kamberaj)</strong> Kamberaj, Low, Neal, J Chem Phys, 122, 224114 (2005).</p>
			<p id="martyna"><strong>(Martyna)</strong> Martyna, Klein, Tuckerman, J Chem Phys, 97, 2635 (1992);
			Martyna, Tuckerman, Tobias, Klein, Mol Phys, 87, 1117.</p>
			<p id="miller"><strong>(Miller)</strong> Miller, Eleftheriou, Pattnaik, Ndirango, and Newns,
			J Chem Phys, 116, 8649 (2002).</p>
			<p id="zhang"><strong>(Zhang)</strong> Zhang, Glotzer, Nanoletters, 4, 1407-1413 (2004).</p>
			</div>
			</div>


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