diff --git a/src/.gitignore b/src/.gitignore
index 02b05b364..0db6a21a7 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -1,1027 +1,1031 @@
 /Makefile.package
 /Makefile.package.settings
 /MAKE/MINE
 /Make.py.last
 /lmp_*
 
 /style_*.h
 
 /*_gpu.h
 /*_gpu.cpp
 /*_intel.h
 /*_intel.cpp
 /*_kokkos.h
 /*_kokkos.cpp
 /*_omp.h
 /*_omp.cpp
 /*_tally.h
 /*_tally.cpp
 /*_rx.h
 /*_rx.cpp
 
 /kokkos.cpp
 /kokkos.h
 /kokkos_type.h
 
 /manifold*.cpp
 /manifold*.h
 /fix_*manifold*.cpp
 /fix_*manifold*.h
 
 /fix_qeq*.cpp
 /fix_qeq*.h
 
 /compute_test_nbl.cpp
 /compute_test_nbl.h
 /pair_multi_lucy.cpp
 /pair_multi_lucy.h
 
 /colvarproxy_lammps.cpp
 /colvarproxy_lammps.h
 /fix_colvars.cpp
 /fix_colvars.h
 /dump_molfile.cpp
 /dump_molfile.h
 /molfile_interface.cpp
 /molfile_interface.h
 /molfile_plugin.h
 /vmdplugin.h
 /type_detector.h
 
 /intel_buffers.cpp
 /intel_buffers.h
 /intel_intrinsics.h
 /intel_preprocess.h
 /intel_simd.h
 
 /compute_sna_atom.cpp
 /compute_sna_atom.h
 /compute_snad_atom.cpp
 /compute_snad_atom.h
 /compute_snav_atom.cpp
 /compute_snav_atom.h
 /openmp_snap.h
 /pair_snap.cpp
 /pair_snap.h
 /sna.cpp
 /sna.h
 
 /atom_vec_wavepacket.cpp
 /atom_vec_wavepacket.h
 /fix_nve_awpmd.cpp
 /fix_nve_awpmd.h
 /pair_awpmd_cut.cpp
 /pair_awpmd_cut.h
 
 /angle_cg_cmm.cpp
 /angle_cg_cmm.h
 /angle_charmm.cpp
 /angle_charmm.h
 /angle_class2.cpp
 /angle_class2.h
 /angle_cosine.cpp
 /angle_cosine.h
 /angle_cosine_delta.cpp
 /angle_cosine_delta.h
 /angle_cosine_periodic.cpp
 /angle_cosine_periodic.h
 /angle_cosine_shift.cpp
 /angle_cosine_shift.h
 /angle_cosine_shift_exp.cpp
 /angle_cosine_shift_exp.h
 /angle_cosine_squared.cpp
 /angle_cosine_squared.h
 /angle_dipole.cpp
 /angle_dipole.h
 /angle_fourier.cpp
 /angle_fourier.h
 /angle_fourier_simple.cpp
 /angle_fourier_simple.h
 /angle_harmonic.cpp
 /angle_harmonic.h
 /angle_quartic.cpp
 /angle_quartic.h
 /angle_sdk.cpp
 /angle_sdk.h
 /angle_table.cpp
 /angle_table.h
 /atom_vec_angle.cpp
 /atom_vec_angle.h
 /atom_vec_bond.cpp
 /atom_vec_bond.h
 /atom_vec_colloid.cpp
 /atom_vec_colloid.h
 /atom_vec_dipole.cpp
 /atom_vec_dipole.h
 /atom_vec_dpd.cpp
 /atom_vec_dpd.h
 /atom_vec_electron.cpp
 /atom_vec_electron.h
 /atom_vec_ellipsoid.cpp
 /atom_vec_ellipsoid.h
 /atom_vec_full.cpp
 /atom_vec_full.h
 /atom_vec_full_hars.cpp
 /atom_vec_full_hars.h
 /atom_vec_granular.cpp
 /atom_vec_granular.h
 /atom_vec_meso.cpp
 /atom_vec_meso.h
 /atom_vec_molecular.cpp
 /atom_vec_molecular.h
 /atom_vec_peri.cpp
 /atom_vec_peri.h
 /atom_vec_template.cpp
 /atom_vec_template.h
 /body_nparticle.cpp
 /body_nparticle.h
 /bond_class2.cpp
 /bond_class2.h
 /bond_fene.cpp
 /bond_fene.h
 /bond_fene_expand.cpp
 /bond_fene_expand.h
 /bond_harmonic.cpp
 /bond_harmonic.h
 /bond_harmonic_shift.cpp
 /bond_harmonic_shift.h
 /bond_harmonic_shift_cut.cpp
 /bond_harmonic_shift_cut.h
 /bond_morse.cpp
 /bond_morse.h
 /bond_nonlinear.cpp
 /bond_nonlinear.h
 /bond_quartic.cpp
 /bond_quartic.h
 /bond_table.cpp
 /bond_table.h
 /cg_cmm_parms.cpp
 /cg_cmm_parms.h
 /commgrid.cpp
 /commgrid.h
 /compute_ackland_atom.cpp
 /compute_ackland_atom.h
 /compute_basal_atom.cpp
 /compute_basal_atom.h
 /compute_body_local.cpp
 /compute_body_local.h
 /compute_cna_atom2.cpp
 /compute_cna_atom2.h
 /compute_damage_atom.cpp
 /compute_damage_atom.h
 /compute_dilatation_atom.cpp
 /compute_dilatation_atom.h
 /compute_dpd.cpp
 /compute_dpd.h
 /compute_dpd_atom.cpp
 /compute_dpd_atom.h
 /compute_erotate_asphere.cpp
 /compute_erotate_asphere.h
 /compute_erotate_rigid.cpp
 /compute_erotate_rigid.h
 /compute_event_displace.cpp
 /compute_event_displace.h
 /compute_fep.cpp
 /compute_fep.h
 /compute_force_tally.cpp
 /compute_force_tally.h
 /compute_heat_flux_tally.cpp
 /compute_heat_flux_tally.h
 /compute_ke_atom_eff.cpp
 /compute_ke_atom_eff.h
 /compute_ke_eff.cpp
 /compute_ke_eff.h
 /compute_ke_rigid.cpp
 /compute_ke_rigid.h
 /compute_meso_e_atom.cpp
 /compute_meso_e_atom.h
 /compute_meso_rho_atom.cpp
 /compute_meso_rho_atom.h
 /compute_meso_t_atom.cpp
 /compute_meso_t_atom.h
 /compute_msd_nongauss.cpp
 /compute_msd_nongauss.h
 /compute_pe_tally.cpp
 /compute_pe_tally.h
 /compute_plasticity_atom.cpp
 /compute_plasticity_atom.h
+/compute_pressure_grem.cpp
+/compute_pressure_grem.h
 /compute_rigid_local.cpp
 /compute_rigid_local.h
 /compute_spec_atom.cpp
 /compute_spec_atom.h
 /compute_stress_tally.cpp
 /compute_stress_tally.h
 /compute_temp_asphere.cpp
 /compute_temp_asphere.h
 /compute_temp_body.cpp
 /compute_temp_body.h
 /compute_temp_deform_eff.cpp
 /compute_temp_deform_eff.h
 /compute_temp_eff.cpp
 /compute_temp_eff.h
 /compute_temp_region_eff.cpp
 /compute_temp_region_eff.h
 /compute_temp_rotate.cpp
 /compute_temp_rotate.h
 /compute_ti.cpp
 /compute_ti.h
 /compute_voronoi_atom.cpp
 /compute_voronoi_atom.h
 /dihedral_charmm.cpp
 /dihedral_charmm.h
 /dihedral_class2.cpp
 /dihedral_class2.h
 /dihedral_cosine_shift_exp.cpp
 /dihedral_cosine_shift_exp.h
 /dihedral_fourier.cpp
 /dihedral_fourier.h
 /dihedral_harmonic.cpp
 /dihedral_harmonic.h
 /dihedral_helix.cpp
 /dihedral_helix.h
 /dihedral_hybrid.cpp
 /dihedral_hybrid.h
 /dihedral_multi_harmonic.cpp
 /dihedral_multi_harmonic.h
 /dihedral_nharmonic.cpp
 /dihedral_nharmonic.h
 /dihedral_opls.cpp
 /dihedral_opls.h
 /dihedral_quadratic.cpp
 /dihedral_quadratic.h
 /dihedral_spherical.cpp
 /dihedral_spherical.h
 /dihedral_table.cpp
 /dihedral_table.h
 /dump_atom_gz.cpp
 /dump_atom_gz.h
 /dump_xyz_gz.cpp
 /dump_xyz_gz.h
 /dump_atom_mpiio.cpp
 /dump_atom_mpiio.h
 /dump_cfg_gz.cpp
 /dump_cfg_gz.h
 /dump_cfg_mpiio.cpp
 /dump_cfg_mpiio.h
 /dump_custom_gz.cpp
 /dump_custom_gz.h
 /dump_custom_mpiio.cpp
 /dump_custom_mpiio.h
 /dump_custom_vtk.cpp
 /dump_custom_vtk.h
 /dump_h5md.cpp
 /dump_h5md.h
 /dump_nc.cpp
 /dump_nc.h
 /dump_nc_mpiio.cpp
 /dump_nc_mpiio.h
 /dump_xtc.cpp
 /dump_xtc.h
 /dump_xyz_mpiio.cpp
 /dump_xyz_mpiio.h
 /ewald.cpp
 /ewald.h
 /ewald_cg.cpp
 /ewald_cg.h
 /ewald_disp.cpp
 /ewald_disp.h
 /ewald_n.cpp
 /ewald_n.h
 /fft3d.cpp
 /fft3d.h
 /fft3d_wrap.cpp
 /fft3d_wrap.h
 /fix_adapt_fep.cpp
 /fix_adapt_fep.h
 /fix_addtorque.cpp
 /fix_addtorque.h
 /fix_append_atoms.cpp
 /fix_append_atoms.h
 /fix_atc.cpp
 /fix_atc.h
 /fix_ave_correlate_long.cpp
 /fix_ave_correlate_long.h
 /fix_bond_break.cpp
 /fix_bond_break.h
 /fix_bond_create.cpp
 /fix_bond_create.h
 /fix_bond_swap.cpp
 /fix_bond_swap.h
 /fix_cmap.cpp
 /fix_cmap.h
 /fix_deposit.cpp
 /fix_deposit.h
 /fix_dpd_energy.cpp
 /fix_dpd_energy.h
 /fix_efield.cpp
 /fix_efield.h
 /fix_eos_cv.cpp
 /fix_eos_cv.h
 /fix_eos_table.cpp
 /fix_eos_table.h
 /fix_evaporate.cpp
 /fix_evaporate.h
 /fix_viscosity.cpp
 /fix_viscosity.h
 /fix_ehex.cpp
 /fix_ehex.h
 /fix_event.cpp
 /fix_event.h
 /fix_event_prd.cpp
 /fix_event_prd.h
 /fix_event_tad.cpp
 /fix_event_tad.h
 /fix_flow_gauss.cpp
 /fix_flow_gauss.h
 /fix_freeze.cpp
 /fix_freeze.h
 /fix_gcmc.cpp
 /fix_gcmc.h
 /fix_gld.cpp
 /fix_gld.h
 /fix_gle.cpp
 /fix_gle.h
 /fix_gpu.cpp
 /fix_gpu.h
+/fix_grem.cpp
+/fix_grem.h
 /fix_imd.cpp
 /fix_imd.h
 /fix_ipi.cpp
 /fix_ipi.h
 /fix_lambdah_calc.cpp
 /fix_lambdah_calc.h
 /fix_langevin_eff.cpp
 /fix_langevin_eff.h
 /fix_lb_fluid.cpp
 /fix_lb_fluid.h
 /fix_lb_momentum.cpp
 /fix_lb_momentum.h
 /fix_lb_pc.cpp
 /fix_lb_pc.h
 /fix_lb_rigid_pc_sphere.cpp
 /fix_lb_rigid_pc_sphere.h
 /fix_lb_viscous.cpp
 /fix_lb_viscous.h
 /fix_load_report.cpp
 /fix_load_report.h
 /fix_meso.cpp
 /fix_meso.h
 /fix_meso_stationary.cpp
 /fix_meso_stationary.h
 /fix_msst.cpp
 /fix_msst.h
 /fix_neb.cpp
 /fix_neb.h
 /fix_nh_asphere.cpp
 /fix_nh_asphere.h
 /fix_nph_asphere.cpp
 /fix_nph_asphere.h
 /fix_npt_asphere.cpp
 /fix_npt_asphere.h
 /fix_nve_asphere.cpp
 /fix_nve_asphere.h
 /fix_nve_asphere_noforce.cpp
 /fix_nve_asphere_noforce.h
 /fix_nh_body.cpp
 /fix_nh_body.h
 /fix_nph_body.cpp
 /fix_nph_body.h
 /fix_npt_body.cpp
 /fix_npt_body.h
 /fix_nvt_body.cpp
 /fix_nvt_body.h
 /fix_nve_body.cpp
 /fix_nve_body.h
 /fix_nvt_asphere.cpp
 /fix_nvt_asphere.h
 /fix_nh_eff.cpp
 /fix_nh_eff.h
 /fix_nph_eff.cpp
 /fix_nph_eff.h
 /fix_nphug.cpp
 /fix_nphug.h
 /fix_npt_eff.cpp
 /fix_npt_eff.h
 /fix_nve_eff.cpp
 /fix_nve_eff.h
 /fix_nve_line.cpp
 /fix_nve_line.h
 /fix_nvt_eff.cpp
 /fix_nvt_eff.h
 /fix_nvt_sllod_eff.cpp
 /fix_nvt_sllod_eff.h
 /fix_nve_tri.cpp
 /fix_nve_tri.h
 /fix_oneway.cpp
 /fix_oneway.h
 /fix_orient_bcc.cpp
 /fix_orient_bcc.h
 /fix_orient_fcc.cpp
 /fix_orient_fcc.h
 /fix_peri_neigh.cpp
 /fix_peri_neigh.h
 /fix_phonon.cpp
 /fix_phonon.h
 /fix_poems.cpp
 /fix_poems.h
 /fix_pour.cpp
 /fix_pour.h
 /fix_qeq_comb.cpp
 /fix_qeq_comb.h
 /fix_qeq_reax.cpp
 /fix_qeq_fire.cpp
 /fix_qeq_fire.h
 /fix_qeq_reax.h
 /fix_qmmm.cpp
 /fix_qmmm.h
 /fix_reax_bonds.cpp
 /fix_reax_bonds.h
 /fix_reax_c.cpp
 /fix_reax_c.h
 /fix_reaxc_bonds.cpp
 /fix_reaxc_bonds.h
 /fix_reaxc_species.cpp
 /fix_reaxc_species.h
 /fix_rigid.cpp
 /fix_rigid.h
 /fix_rigid_nh.cpp
 /fix_rigid_nh.h
 /fix_rigid_nph.cpp
 /fix_rigid_nph.h
 /fix_rigid_npt.cpp
 /fix_rigid_npt.h
 /fix_rigid_nve.cpp
 /fix_rigid_nve.h
 /fix_rigid_nvt.cpp
 /fix_rigid_nvt.h
 /fix_rigid_nh_small.cpp
 /fix_rigid_nh_small.h
 /fix_rigid_nph_small.cpp
 /fix_rigid_nph_small.h
 /fix_rigid_npt_small.cpp
 /fix_rigid_npt_small.h
 /fix_rigid_nve_small.cpp
 /fix_rigid_nve_small.h
 /fix_rigid_nvt_small.cpp
 /fix_rigid_nvt_small.h
 /fix_rigid_small.cpp
 /fix_rigid_small.h
 /fix_shake.cpp
 /fix_shake.h
 /fix_shardlow.cpp
 /fix_shardlow.h
 /fix_smd.cpp
 /fix_smd.h
 /fix_species.cpp
 /fix_species.h
 /fix_spring_pull.cpp
 /fix_spring_pull.h
 /fix_srd.cpp
 /fix_srd.h
 /fix_temp_rescale_eff.cpp
 /fix_temp_rescale_eff.h
 /fix_thermal_conductivity.cpp
 /fix_thermal_conductivity.h
 /fix_ti_rs.cpp
 /fix_ti_rs.h
 /fix_ti_spring.cpp
 /fix_ti_spring.h
 /fix_ttm.cpp
 /fix_ttm.h
 /fix_tune_kspace.cpp
 /fix_tune_kspace.h
 /fix_wall_colloid.cpp
 /fix_wall_colloid.h
 /fix_wall_gran.cpp
 /fix_wall_gran.h
 /fix_wall_gran_region.cpp
 /fix_wall_gran_region.h
 /fix_wall_piston.cpp
 /fix_wall_piston.h
 /fix_wall_srd.cpp
 /fix_wall_srd.h
 /gpu_extra.h
 /gridcomm.cpp
 /gridcomm.h
 /group_ndx.cpp
 /group_ndx.h
 /ndx_group.cpp
 /ndx_group.h
 /improper_class2.cpp
 /improper_class2.h
 /improper_cossq.cpp
 /improper_cossq.h
 /improper_cvff.cpp
 /improper_cvff.h
 /improper_distance.cpp
 /improper_distance.h
 /improper_fourier.cpp
 /improper_fourier.h
 /improper_harmonic.cpp
 /improper_harmonic.h
 /improper_hybrid.cpp
 /improper_hybrid.h
 /improper_ring.cpp
 /improper_ring.h
 /improper_umbrella.cpp
 /improper_umbrella.h
 /kissfft.h
 /lj_sdk_common.h
 /math_complex.h
 /math_vector.h
 /mgpt_*.cpp
 /mgpt_*.h
 /msm.cpp
 /msm.h
 /msm_cg.cpp
 /msm_cg.h
 /neb.cpp
 /neb.h
 
 /pair_adp.cpp
 /pair_adp.h
 /pair_airebo.cpp
 /pair_airebo.h
 /pair_airebo_morse.cpp
 /pair_airebo_morse.h
 /pair_body.cpp
 /pair_body.h
 /pair_bop.cpp
 /pair_bop.h
 /pair_born_coul_long.cpp
 /pair_born_coul_long.h
 /pair_born_coul_msm.cpp
 /pair_born_coul_msm.h
 /pair_brownian.cpp
 /pair_brownian.h
 /pair_brownian_poly.cpp
 /pair_brownian_poly.h
 /pair_buck_coul_long.cpp
 /pair_buck_coul_long.h
 /pair_buck_coul_msm.cpp
 /pair_buck_coul_msm.h
 /pair_buck_coul.cpp
 /pair_buck_coul.h
 /pair_buck_long_coul_long.cpp
 /pair_buck_long_coul_long.h
 /pair_cdeam.cpp
 /pair_cdeam.h
 /pair_cg_cmm.cpp
 /pair_cg_cmm.h
 /pair_cg_cmm_coul_cut.cpp
 /pair_cg_cmm_coul_cut.h
 /pair_cg_cmm_coul_long.cpp
 /pair_cg_cmm_coul_long.h
 /pair_cmm_common.cpp
 /pair_cmm_common.h
 /pair_cg_cmm_coul_msm.cpp
 /pair_cg_cmm_coul_msm.h
 /pair_comb.cpp
 /pair_comb.h
 /pair_comb3.cpp
 /pair_comb3.h
 /pair_colloid.cpp
 /pair_colloid.h
 /pair_coul_diel.cpp
 /pair_coul_diel.h
 /pair_coul_long.cpp
 /pair_coul_long.h
 /pair_coul_msm.cpp
 /pair_coul_msm.h
 /pair_dipole_cut.cpp
 /pair_dipole_cut.h
 /pair_dipole_sf.cpp
 /pair_dipole_sf.h
 /pair_dpd_mt.cpp
 /pair_dpd_mt.h
 /pair_dsmc.cpp
 /pair_dsmc.h
 /pair_eam.cpp
 /pair_eam.h
 /pair_eam_opt.cpp
 /pair_eam_opt.h
 /pair_eam_alloy.cpp
 /pair_eam_alloy.h
 /pair_eam_alloy_opt.cpp
 /pair_eam_alloy_opt.h
 /pair_eam_fs.cpp
 /pair_eam_fs.h
 /pair_eam_fs_opt.cpp
 /pair_eam_fs_opt.h
 /pair_edip.cpp
 /pair_edip.h
 /pair_eff_cut.cpp
 /pair_eff_cut.h
 /pair_eff_inline.h
 /pair_eim.cpp
 /pair_eim.h
 /pair_gauss_cut.cpp
 /pair_gauss_cut.h
 /pair_gayberne.cpp
 /pair_gayberne.h
 /pair_gran_easy.cpp
 /pair_gran_easy.h
 /pair_gran_hertz_history.cpp
 /pair_gran_hertz_history.h
 /pair_gran_hooke.cpp
 /pair_gran_hooke.h
 /pair_gran_hooke_history.cpp
 /pair_gran_hooke_history.h
 /pair_gw.cpp
 /pair_gw.h
 /pair_gw_zbl.cpp
 /pair_gw_zbl.h
 /pair_hbond_dreiding_lj.cpp
 /pair_hbond_dreiding_lj.h
 /pair_hbond_dreiding_morse.cpp
 /pair_hbond_dreiding_morse.h
 /pair_lcbop.cpp
 /pair_lcbop.h
 /pair_line_lj.cpp
 /pair_line_lj.h
 /pair_list.cpp
 /pair_list.h
 /pair_lj_charmm_coul_charmm.cpp
 /pair_lj_charmm_coul_charmm.h
 /pair_lj_charmm_coul_charmm_implicit.cpp
 /pair_lj_charmm_coul_charmm_implicit.h
 /pair_lj_charmm_coul_long.cpp
 /pair_lj_charmm_coul_long.h
 /pair_lj_charmm_coul_long_opt.cpp
 /pair_lj_charmm_coul_long_opt.h
 /pair_lj_charmm_coul_long_soft.cpp
 /pair_lj_charmm_coul_long_soft.h
 /pair_lj_charmm_coul_msm.cpp
 /pair_lj_charmm_coul_msm.h
 /pair_lj_class2.cpp
 /pair_lj_class2.h
 /pair_lj_class2_coul_cut.cpp
 /pair_lj_class2_coul_cut.h
 /pair_lj_class2_coul_long.cpp
 /pair_lj_class2_coul_long.h
 /pair_lj_coul.cpp
 /pair_lj_coul.h
 /pair_coul_cut_soft.cpp
 /pair_coul_cut_soft.h
 /pair_coul_long_soft.cpp
 /pair_coul_long_soft.h
 /pair_lj_cut_coul_cut_soft.cpp
 /pair_lj_cut_coul_cut_soft.h
 /pair_lj_cut_tip4p_cut.cpp
 /pair_lj_cut_tip4p_cut.h
 /pair_lj_cut_coul_long.cpp
 /pair_lj_cut_coul_long.h
 /pair_lj_cut_coul_long_opt.cpp
 /pair_lj_cut_coul_long_opt.h
 /pair_lj_cut_coul_long_soft.cpp
 /pair_lj_cut_coul_long_soft.h
 /pair_lj_cut_coul_msm.cpp
 /pair_lj_cut_coul_msm.h
 /pair_lj_cut_dipole_cut.cpp
 /pair_lj_cut_dipole_cut.h
 /pair_lj_cut_dipole_long.cpp
 /pair_lj_cut_dipole_long.h
 /pair_lj_cut_*hars_*.cpp
 /pair_lj_cut_*hars_*.h
 /pair_lj_cut_soft.cpp
 /pair_lj_cut_soft.h
 /pair_lj_cut_tip4p_long.cpp
 /pair_lj_cut_tip4p_long.h
 /pair_lj_cut_tip4p_long_opt.cpp
 /pair_lj_cut_tip4p_long_opt.h
 /pair_lj_cut_tip4p_long_soft.cpp
 /pair_lj_cut_tip4p_long_soft.h
 /pair_lj_long_coul_long.cpp
 /pair_lj_long_coul_long.h
 /pair_lj_long_coul_long_opt.cpp
 /pair_lj_long_coul_long_opt.h
 /pair_lj_long_dipole_long.cpp
 /pair_lj_long_dipole_long.h
 /pair_lj_long_tip4p_long.cpp
 /pair_lj_long_tip4p_long.h
 /pair_lj_cut_opt.cpp
 /pair_lj_cut_opt.h
 /pair_lj_cut_tgpu.cpp
 /pair_lj_cut_tgpu.h
 /pair_lj_sdk.cpp
 /pair_lj_sdk.h
 /pair_lj_sdk_coul_long.cpp
 /pair_lj_sdk_coul_long.h
 /pair_lj_sdk_coul_msm.cpp
 /pair_lj_sdk_coul_msm.h
 /pair_lj_sf.cpp
 /pair_lj_sf.h
 /pair_lj_sf_dipole_sf.cpp
 /pair_lj_sf_dipole_sf.h
 /pair_lubricateU.cpp
 /pair_lubricateU.h
 /pair_lubricateU_poly.cpp
 /pair_lubricateU_poly.h
 /pair_lubricate_poly.cpp
 /pair_lubricate_poly.h
 /pair_lubricate.cpp
 /pair_lubricate.h
 /pair_meam.cpp
 /pair_meam.h
 /pair_meam_spline.cpp
 /pair_meam_spline.h
 /pair_meam_sw_spline.cpp
 /pair_meam_sw_spline.h
 /pair_morse_opt.cpp
 /pair_morse_opt.h
 /pair_morse_soft.cpp
 /pair_morse_soft.h
 /pair_nb3b_harmonic.cpp
 /pair_nb3b_harmonic.h
 /pair_nm_cut.cpp
 /pair_nm_cut.h
 /pair_nm_cut_coul_cut.cpp
 /pair_nm_cut_coul_cut.h
 /pair_nm_cut_coul_long.cpp
 /pair_nm_cut_coul_long.h
 /pair_peri_eps.cpp
 /pair_peri_eps.h
 /pair_peri_lps.cpp
 /pair_peri_lps.h
 /pair_peri_pmb.cpp
 /pair_peri_pmb.h
 /pair_peri_ves.cpp
 /pair_peri_ves.h
 /pair_reax.cpp
 /pair_reax.h
 /pair_reax_fortran.h
 /pair_reax_c.cpp
 /pair_reax_c.h
 /pair_rebo.cpp
 /pair_rebo.h
 /pair_resquared.cpp
 /pair_resquared.h
 /pair_sph_heatconduction.cpp
 /pair_sph_heatconduction.h
 /pair_sph_idealgas.cpp
 /pair_sph_idealgas.h
 /pair_sph_lj.cpp
 /pair_sph_lj.h
 /pair_sph_rhosum.cpp
 /pair_sph_rhosum.h
 /pair_sph_taitwater.cpp
 /pair_sph_taitwater.h
 /pair_sph_taitwater_morris.cpp
 /pair_sph_taitwater_morris.h
 /pair_sw.cpp
 /pair_sw.h
 /pair_tersoff.cpp
 /pair_tersoff.h
 /pair_tersoff_mod.cpp
 /pair_tersoff_mod.h
 /pair_tersoff_table.cpp
 /pair_tersoff_table.h
 /pair_tersoff_zbl.cpp
 /pair_tersoff_zbl.h
 /pair_tip4p_cut.cpp
 /pair_tip4p_cut.h
 /pair_tip4p_long.cpp
 /pair_tip4p_long.h
 /pair_tip4p_long_soft.cpp
 /pair_tip4p_long_soft.h
 /pair_tri_lj.cpp
 /pair_tri_lj.h
 /pair_yukawa_colloid.cpp
 /pair_yukawa_colloid.h
 /pppm.cpp
 /pppm.h
 /pppm_cg.cpp
 /pppm_cg.h
 /pppm_disp.cpp
 /pppm_disp.h
 /pppm_disp_tip4p.cpp
 /pppm_disp_tip4p.h
 /pppm_old.cpp
 /pppm_old.h
 /pppm_proxy.cpp
 /pppm_proxy.h
 /pppm_stagger.cpp
 /pppm_stagger.h
 /pppm_tip4p.cpp
 /pppm_tip4p.h
 /pppm_tip4p_proxy.cpp
 /pppm_tip4p_proxy.h
 /pppm_tip4p_cg.cpp
 /pppm_tip4p_cg.h
 /prd.cpp
 /prd.h
 /python.cpp
 /python.h
 /reader_molfile.cpp
 /reader_molfile.h
 /reaxc_allocate.cpp
 /reaxc_allocate.h
 /reaxc_basic_comm.cpp
 /reaxc_basic_comm.h
 /reaxc_bond_orders.cpp
 /reaxc_bond_orders.h
 /reaxc_bonds.cpp
 /reaxc_bonds.h
 /reaxc_control.cpp
 /reaxc_control.h
 /reaxc_defs.h
 /reaxc_ffield.cpp
 /reaxc_ffield.h
 /reaxc_forces.cpp
 /reaxc_forces.h
 /reaxc_hydrogen_bonds.cpp
 /reaxc_hydrogen_bonds.h
 /reaxc_init_md.cpp
 /reaxc_init_md.h
 /reaxc_io_tools.cpp
 /reaxc_io_tools.h
 /reaxc_list.cpp
 /reaxc_list.h
 /reaxc_lookup.cpp
 /reaxc_lookup.h
 /reaxc_multi_body.cpp
 /reaxc_multi_body.h
 /reaxc_nonbonded.cpp
 /reaxc_nonbonded.h
 /reaxc_reset_tools.cpp
 /reaxc_reset_tools.h
 /reaxc_system_props.cpp
 /reaxc_system_props.h
 /reaxc_tool_box.cpp
 /reaxc_tool_box.h
 /reaxc_torsion_angles.cpp
 /reaxc_torsion_angles.h
 /reaxc_traj.cpp
 /reaxc_traj.h
 /reaxc_types.h
 /reaxc_valence_angles.cpp
 /reaxc_valence_angles.h
 /reaxc_vector.cpp
 /reaxc_vector.h
 /remap.cpp
 /remap.h
 /remap_wrap.cpp
 /remap_wrap.h
 /restart_mpiio.cpp
 /restart_mpiio.h
 /smd_kernels.h
 /smd_material_models.cpp
 /smd_material_models.h
 /smd_math.h
 /tad.cpp
 /tad.h
 /temper.cpp
 /temper.h
 /thr_data.cpp
 /thr_data.h
 /verlet_split.cpp
 /verlet_split.h
 /write_dump.cpp
 /write_dump.h
 /xdr_compat.cpp
 /xdr_compat.h
 
 /atom_vec_smd.cpp
 /atom_vec_smd.h
 /compute_saed.cpp
 /compute_saed.h
 /compute_saed_consts.h
 /compute_smd_contact_radius.cpp
 /compute_smd_contact_radius.h
 /compute_smd_damage.cpp
 /compute_smd_damage.h
 /compute_smd_hourglass_error.cpp
 /compute_smd_hourglass_error.h
 /compute_smd_internal_energy.cpp
 /compute_smd_internal_energy.h
 /compute_smd_plastic_strain.cpp
 /compute_smd_plastic_strain.h
 /compute_smd_plastic_strain_rate.cpp
 /compute_smd_plastic_strain_rate.h
 /compute_smd_rho.cpp
 /compute_smd_rho.h
 /compute_smd_tlsph_defgrad.cpp
 /compute_smd_tlsph_defgrad.h
 /compute_smd_tlsph_dt.cpp
 /compute_smd_tlsph_dt.h
 /compute_smd_tlsph_num_neighs.cpp
 /compute_smd_tlsph_num_neighs.h
 /compute_smd_tlsph_shape.cpp
 /compute_smd_tlsph_shape.h
 /compute_smd_tlsph_strain.cpp
 /compute_smd_tlsph_strain.h
 /compute_smd_tlsph_strain_rate.cpp
 /compute_smd_tlsph_strain_rate.h
 /compute_smd_tlsph_stress.cpp
 /compute_smd_tlsph_stress.h
 /compute_smd_triangle_mesh_vertices.cpp
 /compute_smd_triangle_mesh_vertices.h
 /compute_smd_ulsph_effm.cpp
 /compute_smd_ulsph_effm.h
 /compute_smd_ulsph_num_neighs.cpp
 /compute_smd_ulsph_num_neighs.h
 /compute_smd_ulsph_strain.cpp
 /compute_smd_ulsph_strain.h
 /compute_smd_ulsph_strain_rate.cpp
 /compute_smd_ulsph_strain_rate.h
 /compute_smd_ulsph_stress.cpp
 /compute_smd_ulsph_stress.h
 /compute_smd_vol.cpp
 /compute_smd_vol.h
 /compute_temp_cs.cpp
 /compute_temp_cs.h
 /compute_temp_drude.cpp
 /compute_temp_drude.h
 /compute_xrd.cpp
 /compute_xrd.h
 /compute_xrd_consts.h
 /fix_atom_swap.cpp
 /fix_atom_swap.h
 /fix_ave_spatial_sphere.cpp
 /fix_ave_spatial_sphere.h
 /fix_drude.cpp
 /fix_drude.h
 /fix_drude_transform.cpp
 /fix_drude_transform.h
 /fix_langevin_drude.cpp
 /fix_langevin_drude.h
 /fix_pimd.cpp
 /fix_pimd.h
 /fix_qbmsst.cpp
 /fix_qbmsst.h
 /fix_qtb.cpp
 /fix_qtb.h
 /fix_rattle.cpp
 /fix_rattle.h
 /fix_saed_vtk.cpp
 /fix_saed_vtk.h
 /fix_smd_adjust_dt.cpp
 /fix_smd_adjust_dt.h
 /fix_smd_integrate_tlsph.cpp
 /fix_smd_integrate_tlsph.h
 /fix_smd_integrate_ulsph.cpp
 /fix_smd_integrate_ulsph.h
 /fix_smd_move_triangulated_surface.cpp
 /fix_smd_move_triangulated_surface.h
 /fix_smd_setvel.cpp
 /fix_smd_setvel.h
 /fix_smd_tlsph_reference_configuration.cpp
 /fix_smd_tlsph_reference_configuration.h
 /fix_smd_wall_surface.cpp
 /fix_smd_wall_surface.h
 /fix_srp.cpp
 /fix_srp.h
 /fix_tfmc.cpp
 /fix_tfmc.h
 /fix_ttm_mod.cpp
 /fix_ttm_mod.h
 /pair_born_coul_long_cs.cpp
 /pair_born_coul_long_cs.h
 /pair_born_coul_dsf_cs.cpp
 /pair_born_coul_dsf_cs.h
 /pair_buck_coul_long_cs.cpp
 /pair_buck_coul_long_cs.h
 /pair_coul_long_cs.cpp
 /pair_coul_long_cs.h
 /pair_lj_cut_thole_long.cpp
 /pair_lj_cut_thole_long.h
 /pair_plum_hb.cpp
 /pair_plum_hb.h
 /pair_plum_hp.cpp
 /pair_plum_hp.h
 /pair_polymorphic.cpp
 /pair_polymorphic.h
 /pair_smd_hertz.cpp
 /pair_smd_hertz.h
 /pair_smd_tlsph.cpp
 /pair_smd_tlsph.h
 /pair_smd_triangulated_surface.cpp
 /pair_smd_triangulated_surface.h
 /pair_smd_ulsph.cpp
 /pair_smd_ulsph.h
 /pair_srp.cpp
 /pair_srp.h
 /pair_thole.cpp
 /pair_thole.h
 /pair_buck_mdf.cpp
 /pair_buck_mdf.h
 /pair_dpd_conservative.cpp
 /pair_dpd_conservative.h
 /pair_dpd_fdt.cpp
 /pair_dpd_fdt.h
 /pair_dpd_fdt_energy.cpp
 /pair_dpd_fdt_energy.h
 /pair_lennard_mdf.cpp
 /pair_lennard_mdf.h
 /pair_lj_cut_coul_long_cs.cpp
 /pair_lj_cut_coul_long_cs.h
 /pair_lj_mdf.cpp
 /pair_lj_mdf.h
 /pair_mgpt.cpp
 /pair_mgpt.h
 /pair_morse_smooth_linear.cpp
 /pair_morse_smooth_linear.h
 /pair_smtbq.cpp
 /pair_smtbq.h
 /pair_vashishta*.cpp
 /pair_vashishta*.h
 
diff --git a/src/USER-MISC/compute_pressure_grem.cpp b/src/USER-MISC/compute_pressure_grem.cpp
new file mode 100644
index 000000000..387bde642
--- /dev/null
+++ b/src/USER-MISC/compute_pressure_grem.cpp
@@ -0,0 +1,149 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include <mpi.h>
+#include <string.h>
+#include <stdlib.h>
+#include "compute_pressure_grem.h"
+#include "atom.h"
+#include "update.h"
+#include "domain.h"
+#include "modify.h"
+#include "fix.h"
+#include "force.h"
+#include "pair.h"
+#include "kspace.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ----------------------------------------------------------------------
+   Last argument is the id of the gREM fix
+------------------------------------------------------------------------- */
+
+ComputePressureGrem::ComputePressureGrem(LAMMPS *lmp, int narg, char **arg) :
+  ComputePressure(lmp, narg-1, arg)
+{
+  fix_grem = arg[narg-1];
+}
+
+/* ---------------------------------------------------------------------- */
+
+void ComputePressureGrem::init()
+{
+  ComputePressure::init();
+
+  // Initialize hook to gREM fix
+  int ifix = modify->find_fix(fix_grem);
+  if (ifix < 0)
+    error->all(FLERR,"Fix grem ID for compute pressure/grem does not exist");
+
+  int dim;
+  scale_grem = (double *)modify->fix[ifix]->extract("scale_grem",dim);
+
+  if (scale_grem == NULL || dim != 0)
+    error->all(FLERR,"Cannot extract gREM scale factor from fix grem");
+}
+
+/* ----------------------------------------------------------------------
+   compute total pressure, averaged over Pxx, Pyy, Pzz
+------------------------------------------------------------------------- */
+
+double ComputePressureGrem::compute_scalar()
+{
+  invoked_scalar = update->ntimestep;
+  if (update->vflag_global != invoked_scalar)
+    error->all(FLERR,"Virial was not tallied on needed timestep");
+
+  // invoke temperature if it hasn't been already
+
+  double t;
+  if (keflag) {
+    if (temperature->invoked_scalar != update->ntimestep)
+      t = temperature->compute_scalar() * (*scale_grem);
+    else t = temperature->scalar * (*scale_grem);
+  }
+
+  if (dimension == 3) {
+    inv_volume = 1.0 / (domain->xprd * domain->yprd * domain->zprd);
+    virial_compute(3,3);
+    if (keflag)
+      scalar = (temperature->dof * boltz * t +
+                virial[0] + virial[1] + virial[2]) / 3.0 * inv_volume * nktv2p;
+    else
+      scalar = (virial[0] + virial[1] + virial[2]) / 3.0 * inv_volume * nktv2p;
+  } else {
+    inv_volume = 1.0 / (domain->xprd * domain->yprd);
+    virial_compute(2,2);
+    if (keflag)
+      scalar = (temperature->dof * boltz * t +
+                virial[0] + virial[1]) / 2.0 * inv_volume * nktv2p;
+    else
+      scalar = (virial[0] + virial[1]) / 2.0 * inv_volume * nktv2p;
+  }
+
+  return scalar;
+}
+
+/* ----------------------------------------------------------------------
+   compute pressure tensor
+   assume KE tensor has already been computed
+------------------------------------------------------------------------- */
+
+void ComputePressureGrem::compute_vector()
+{
+  invoked_vector = update->ntimestep;
+  if (update->vflag_global != invoked_vector)
+    error->all(FLERR,"Virial was not tallied on needed timestep");
+
+  if (force->kspace && kspace_virial && force->kspace->scalar_pressure_flag)
+    error->all(FLERR,"Must use 'kspace_modify pressure/scalar no' for "
+	       "tensor components with kspace_style msm");
+
+  // invoke temperature if it hasn't been already
+
+  double *ke_tensor;
+  if (keflag) {
+    if (temperature->invoked_vector != update->ntimestep)
+      temperature->compute_vector();
+    ke_tensor = temperature->vector;
+  }
+  for (int i = 0; i < 6; i++)
+    ke_tensor[i] *= *scale_grem;
+
+  if (dimension == 3) {
+    inv_volume = 1.0 / (domain->xprd * domain->yprd * domain->zprd);
+    virial_compute(6,3);
+    if (keflag) {
+      for (int i = 0; i < 6; i++)
+        vector[i] = (ke_tensor[i] + virial[i]) * inv_volume * nktv2p;
+    } else
+      for (int i = 0; i < 6; i++)
+        vector[i] = virial[i] * inv_volume * nktv2p;
+  } else {
+    inv_volume = 1.0 / (domain->xprd * domain->yprd);
+    virial_compute(4,2);
+    if (keflag) {
+      vector[0] = (ke_tensor[0] + virial[0]) * inv_volume * nktv2p;
+      vector[1] = (ke_tensor[1] + virial[1]) * inv_volume * nktv2p;
+      vector[3] = (ke_tensor[3] + virial[3]) * inv_volume * nktv2p;
+      vector[2] = vector[4] = vector[5] = 0.0;
+    } else {
+      vector[0] = virial[0] * inv_volume * nktv2p;
+      vector[1] = virial[1] * inv_volume * nktv2p;
+      vector[3] = virial[3] * inv_volume * nktv2p;
+      vector[2] = vector[4] = vector[5] = 0.0;
+    }
+  }
+}
+
diff --git a/src/compute_pressure.h b/src/USER-MISC/compute_pressure_grem.h
similarity index 73%
copy from src/compute_pressure.h
copy to src/USER-MISC/compute_pressure_grem.h
index 4ff116837..8d30af932 100644
--- a/src/compute_pressure.h
+++ b/src/USER-MISC/compute_pressure_grem.h
@@ -1,92 +1,91 @@
 /* -*- c++ -*- ----------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
    http://lammps.sandia.gov, Sandia National Laboratories
    Steve Plimpton, sjplimp@sandia.gov
 
    Copyright (2003) Sandia Corporation.  Under the terms of Contract
    DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
    certain rights in this software.  This software is distributed under
    the GNU General Public License.
 
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
 #ifdef COMPUTE_CLASS
 
-ComputeStyle(pressure,ComputePressure)
+ComputeStyle(pressure/grem,ComputePressureGrem)
 
 #else
 
-#ifndef LMP_COMPUTE_PRESSURE_H
-#define LMP_COMPUTE_PRESSURE_H
+#ifndef LMP_COMPUTE_PRESSURE_GREM_H
+#define LMP_COMPUTE_PRESSURE_GREM_H
 
-#include "compute.h"
+#include "compute_pressure.h"
 
 namespace LAMMPS_NS {
 
-class ComputePressure : public Compute {
+class ComputePressureGrem : public ComputePressure {
  public:
-  ComputePressure(class LAMMPS *, int, char **);
-  virtual ~ComputePressure();
-  void init();
-  double compute_scalar();
-  void compute_vector();
-  void reset_extra_compute_fix(const char *);
+  ComputePressureGrem(class LAMMPS *, int, char **);
+  virtual ~ComputePressureGrem() {};
+  virtual void init();
+  virtual double compute_scalar();
+  virtual void compute_vector();
 
  protected:
-  double boltz,nktv2p,inv_volume;
-  int nvirial,dimension;
-  double **vptr;
-  double *kspace_virial;
-  Compute *temperature;
-  char *id_temp;
-  double virial[6];
-  int keflag,pairflag,bondflag,angleflag,dihedralflag,improperflag;
-  int fixflag,kspaceflag;
-
-  void virial_compute(int, int);
+  // Access to gREM fix scale factor
+  char   *fix_grem;
+  double *scale_grem;
 };
 
 }
 
 #endif
 #endif
 
 /* ERROR/WARNING messages:
 
 E: Illegal ... command
 
 Self-explanatory.  Check the input script syntax and compare to the
 documentation for the command.  You can use -echo screen as a
 command-line option when running LAMMPS to see the offending line.
 
 E: Compute pressure must use group all
 
 Virial contributions computed by potentials (pair, bond, etc) are
 computed on all atoms.
 
 E: Could not find compute pressure temperature ID
 
 The compute ID for calculating temperature does not exist.
 
 E: Compute pressure temperature ID does not compute temperature
 
 The compute ID assigned to a pressure computation must compute
 temperature.
 
 E: Compute pressure requires temperature ID to include kinetic energy
 
 The keflag cannot be used unless a temperature compute is provided.
 
 E: Virial was not tallied on needed timestep
 
 You are using a thermo keyword that requires potentials to
 have tallied the virial, but they didn't on this timestep.  See the
 variable doc page for ideas on how to make this work.
 
 E: Must use 'kspace_modify pressure/scalar no' for tensor components with kspace_style msm
 
 Otherwise MSM will compute only a scalar pressure.  See the kspace_modify
 command for details on this setting.
 
+E: Fix grem ID for compute pressure/grem does not exist
+
+Compute pressure/grem was passed an invalid fix id
+
+E: Cannot extract gREM scale factor from fix grem
+
+The fix id passed to compute pressure/grem refers to an incompatible fix
+
 */
diff --git a/src/USER-MISC/fix_grem.cpp b/src/USER-MISC/fix_grem.cpp
new file mode 100644
index 000000000..7778052d2
--- /dev/null
+++ b/src/USER-MISC/fix_grem.cpp
@@ -0,0 +1,239 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+
+   Force scaling fix for gREM.
+   Cite: http://dx.doi.org/10.1063/1.3432176
+   Cite: http://dx.doi.org/10.1021/acs.jpcb.5b07614
+   
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing author: Edyta Malolepsza (Broad Institute)
+   Contributing author: David Stelter (Boston University)
+   Contributing author: Tom Keyes (Boston University)
+------------------------------------------------------------------------- */
+
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+#include "comm.h"
+#include "fix_grem.h"
+#include "atom.h"
+#include "force.h"
+#include "update.h"
+#include "modify.h"
+#include "domain.h"
+#include "input.h"
+#include "compute.h"
+#include "memory.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+using namespace FixConst;
+
+enum{NONE,CONSTANT,EQUAL,ATOM};
+
+/* ---------------------------------------------------------------------- */
+
+FixGrem::FixGrem(LAMMPS *lmp, int narg, char **arg) :
+  Fix(lmp, narg, arg)
+{
+  if (narg < 8) error->all(FLERR,"Illegal fix grem command");
+
+  scalar_flag = 1;
+  vector_flag = 1;
+  size_vector = 3;
+  global_freq = 1;
+  extscalar = 1;
+  extvector = 1;
+
+  // tbath - temp of bath, the same as defined in thermostat
+
+  lambda = force->numeric(FLERR,arg[3]);
+  eta = force->numeric(FLERR,arg[4]);
+  h0 = force->numeric(FLERR,arg[5]);
+  tbath = force->numeric(FLERR,arg[6]);
+  pressref = force->numeric(FLERR,arg[7]);
+
+  // create a new compute temp style
+  // id = fix-ID + temp
+  // compute group = all since pressure is always global (group all)
+  //   and thus its KE/temperature contribution should use group all
+
+  int n = strlen(id) + 6;
+  id_temp = new char[n];
+  strcpy(id_temp,id);
+  strcat(id_temp,"_temp");
+
+  char **newarg = new char*[3];
+  newarg[0] = id_temp;
+  newarg[1] = (char *) "all";
+  newarg[2] = (char *) "temp";
+  modify->add_compute(3,newarg);
+  delete [] newarg;
+  tflag = 1;
+
+  // create a new compute pressure style
+  // id = fix-ID + press, compute group = all
+  // pass id_temp as 4th arg to pressure constructor
+
+  n = strlen(id) + 7;
+  id_press = new char[n];
+  strcpy(id_press,id);
+  strcat(id_press,"_press");
+
+  newarg = new char*[5];
+  newarg[0] = id_press;
+  newarg[1] = (char *) "all";
+  newarg[2] = (char *) "pressure/grem";
+  newarg[3] = id_temp;
+  newarg[4] = id;
+  modify->add_compute(5,newarg);
+  delete [] newarg;
+  
+  // create a new compute ke style
+  // id = fix-ID + ke
+
+  n = strlen(id) + 8;
+  id_ke = new char[n];
+  strcpy(id_ke,id);
+  strcat(id_ke,"_ke");
+
+  newarg = new char*[3];
+  newarg[0] = id_ke;
+  newarg[1] = (char *) "all";
+  newarg[2] = (char *) "ke";
+  modify->add_compute(3,newarg);
+  delete [] newarg;
+  keflag = 1;
+
+  // create a new compute pe style
+  // id = fix-ID + pe
+
+  n = strlen(id) + 9;
+  id_pe = new char[n];
+  strcpy(id_pe,id);
+  strcat(id_pe,"_pe");
+
+  newarg = new char*[3];
+  newarg[0] = id_pe;
+  newarg[1] = (char *) "all";
+  newarg[2] = (char *) "pe";
+  modify->add_compute(3,newarg);
+  delete [] newarg;
+  peflag = 1;
+
+}
+
+/* ---------------------------------------------------------------------- */
+
+FixGrem::~FixGrem()
+{
+  // delete temperature, pressure and energies if fix created them
+
+  if (tflag) modify->delete_compute(id_temp);
+  if (pflag) modify->delete_compute(id_press);
+  if (keflag) modify->delete_compute(id_ke);
+  if (peflag) modify->delete_compute(id_pe);
+  delete [] id_temp;
+  delete [] id_press;
+  delete [] id_ke;
+  delete [] id_pe;
+
+}
+
+/* ---------------------------------------------------------------------- */
+
+int FixGrem::setmask()
+{
+  int mask = 0;
+  mask |= POST_FORCE;
+  return mask;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGrem::init()
+{
+
+  // add check of sign of eta
+
+  // set temperature and pressure ptrs
+
+  int icompute = modify->find_compute(id_temp);
+  if (icompute < 0)
+    error->all(FLERR,"Temperature ID for fix scaledforce does not exist");
+  temperature = modify->compute[icompute];
+
+  icompute = modify->find_compute(id_ke);
+  if (icompute < 0)
+    error->all(FLERR,"Ke ID for fix scaledforce does not exist");
+  ke = modify->compute[icompute];
+
+  icompute = modify->find_compute(id_pe);
+  if (icompute < 0)
+    error->all(FLERR,"Pe ID for fix scaledforce does not exist");
+  pe = modify->compute[icompute];  
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGrem::setup(int vflag)
+{
+  if (strstr(update->integrate_style,"verlet"))
+    post_force(vflag);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGrem::min_setup(int vflag)
+{
+  post_force(vflag);
+}
+
+/* ---------------------------------------------------------------------- */
+
+void FixGrem::post_force(int vflag)
+{
+  double **f = atom->f;
+  int *mask = atom->mask;
+  int nlocal = atom->nlocal;
+  
+  double tmpvolume = domain->xprd * domain->yprd * domain->zprd;
+  double tmppe = pe->compute_scalar();
+  // potential energy
+  double tmpenthalpy = tmppe+pressref*tmpvolume/(force->nktv2p);
+
+  double teffective = lambda+eta*(tmpenthalpy-h0);
+  scale_grem = tbath/teffective;
+  
+  for (int i = 0; i < nlocal; i++)
+    if (mask[i] & groupbit) {
+      f[i][0] *= scale_grem;
+      f[i][1] *= scale_grem;
+      f[i][2] *= scale_grem;
+    }
+  pe->addstep(update->ntimestep+1);
+}
+
+/* ----------------------------------------------------------------------
+   extract scale factor
+------------------------------------------------------------------------- */
+
+void *FixGrem::extract(const char *str, int &dim)
+{
+  dim=0;
+  if (strcmp(str,"scale_grem") == 0) {
+    return &scale_grem;
+  }
+  return NULL;
+}
diff --git a/src/USER-MISC/fix_grem.h b/src/USER-MISC/fix_grem.h
new file mode 100644
index 000000000..e5087436b
--- /dev/null
+++ b/src/USER-MISC/fix_grem.h
@@ -0,0 +1,84 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifdef FIX_CLASS
+
+FixStyle(grem,FixGrem)
+
+#else
+
+#ifndef LMP_FIX_GREM_H
+#define LMP_FIX_GREM_H
+
+#include "fix.h"
+
+namespace LAMMPS_NS {
+
+class FixGrem : public Fix {
+ public:
+  FixGrem(class LAMMPS *, int, char **);
+  ~FixGrem();
+  int setmask();
+  void init();
+  void setup(int);
+  void min_setup(int);
+  void post_force(int);
+  void *extract(const char *, int &);
+  double scale_grem;
+
+ private:
+  double lambda,eta,h0,tbath,pressref;
+
+ protected:
+  char *id_temp,*id_press,*id_ke,*id_pe;
+  class Compute *temperature,*pressure,*ke,*pe;
+  int pflag,tflag,keflag,peflag;
+
+};
+
+}
+
+#endif
+#endif
+
+/* ERROR/WARNING messages:
+
+E: Illegal ... command
+
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
+
+E: Region ID for fix grem does not exist
+
+Self-explanatory.
+
+E: Variable name for fix grem does not exist
+
+Self-explanatory.
+
+E: Variable for fix grem is invalid style
+
+Self-explanatory.
+
+E: Cannot use variable energy with constant force in fix grem
+
+This is because for constant force, LAMMPS can compute the change
+in energy directly.
+
+E: Must use variable energy with fix grem
+
+Must define an energy vartiable when applyting a dynamic
+force during minimization.
+
+*/
diff --git a/src/compute_pressure.h b/src/compute_pressure.h
index 4ff116837..a59a64e63 100644
--- a/src/compute_pressure.h
+++ b/src/compute_pressure.h
@@ -1,92 +1,92 @@
 /* -*- c++ -*- ----------------------------------------------------------
    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
    http://lammps.sandia.gov, Sandia National Laboratories
    Steve Plimpton, sjplimp@sandia.gov
 
    Copyright (2003) Sandia Corporation.  Under the terms of Contract
    DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
    certain rights in this software.  This software is distributed under
    the GNU General Public License.
 
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
 #ifdef COMPUTE_CLASS
 
 ComputeStyle(pressure,ComputePressure)
 
 #else
 
 #ifndef LMP_COMPUTE_PRESSURE_H
 #define LMP_COMPUTE_PRESSURE_H
 
 #include "compute.h"
 
 namespace LAMMPS_NS {
 
 class ComputePressure : public Compute {
  public:
   ComputePressure(class LAMMPS *, int, char **);
   virtual ~ComputePressure();
-  void init();
-  double compute_scalar();
-  void compute_vector();
+  virtual void init();
+  virtual double compute_scalar();
+  virtual void compute_vector();
   void reset_extra_compute_fix(const char *);
 
  protected:
   double boltz,nktv2p,inv_volume;
   int nvirial,dimension;
   double **vptr;
   double *kspace_virial;
   Compute *temperature;
   char *id_temp;
   double virial[6];
   int keflag,pairflag,bondflag,angleflag,dihedralflag,improperflag;
   int fixflag,kspaceflag;
 
   void virial_compute(int, int);
 };
 
 }
 
 #endif
 #endif
 
 /* ERROR/WARNING messages:
 
 E: Illegal ... command
 
 Self-explanatory.  Check the input script syntax and compare to the
 documentation for the command.  You can use -echo screen as a
 command-line option when running LAMMPS to see the offending line.
 
 E: Compute pressure must use group all
 
 Virial contributions computed by potentials (pair, bond, etc) are
 computed on all atoms.
 
 E: Could not find compute pressure temperature ID
 
 The compute ID for calculating temperature does not exist.
 
 E: Compute pressure temperature ID does not compute temperature
 
 The compute ID assigned to a pressure computation must compute
 temperature.
 
 E: Compute pressure requires temperature ID to include kinetic energy
 
 The keflag cannot be used unless a temperature compute is provided.
 
 E: Virial was not tallied on needed timestep
 
 You are using a thermo keyword that requires potentials to
 have tallied the virial, but they didn't on this timestep.  See the
 variable doc page for ideas on how to make this work.
 
 E: Must use 'kspace_modify pressure/scalar no' for tensor components with kspace_style msm
 
 Otherwise MSM will compute only a scalar pressure.  See the kspace_modify
 command for details on this setting.
 
 */