diff --git a/doc/src/Section_commands.txt b/doc/src/Section_commands.txt index 010454b87..0d46a0142 100644 --- a/doc/src/Section_commands.txt +++ b/doc/src/Section_commands.txt @@ -1,1248 +1,1249 @@ "Previous Section"_Section_start.html - "LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc - "Next Section"_Section_packages.html :c :link(lws,http://lammps.sandia.gov) :link(ld,Manual.html) :link(lc,Section_commands.html#comm) :line 3. Commands :h3 This section describes how a LAMMPS input script is formatted and the input script commands used to define a LAMMPS simulation. 3.1 "LAMMPS input script"_#cmd_1 3.2 "Parsing rules"_#cmd_2 3.3 "Input script structure"_#cmd_3 3.4 "Commands listed by category"_#cmd_4 3.5 "Commands listed alphabetically"_#cmd_5 :all(b) :line :line 3.1 LAMMPS input script :link(cmd_1),h4 LAMMPS executes by reading commands from a input script (text file), one line at a time. When the input script ends, LAMMPS exits. Each command causes LAMMPS to take some action. It may set an internal variable, read in a file, or run a simulation. Most commands have default settings, which means you only need to use the command if you wish to change the default. In many cases, the ordering of commands in an input script is not important. However the following rules apply: (1) LAMMPS does not read your entire input script and then perform a simulation with all the settings. Rather, the input script is read one line at a time and each command takes effect when it is read. Thus this sequence of commands: timestep 0.5 run 100 run 100 :pre does something different than this sequence: run 100 timestep 0.5 run 100 :pre In the first case, the specified timestep (0.5 fmsec) is used for two simulations of 100 timesteps each. In the 2nd case, the default timestep (1.0 fmsec) is used for the 1st 100 step simulation and a 0.5 fmsec timestep is used for the 2nd one. (2) Some commands are only valid when they follow other commands. For example you cannot set the temperature of a group of atoms until atoms have been defined and a group command is used to define which atoms belong to the group. (3) Sometimes command B will use values that can be set by command A. This means command A must precede command B in the input script if it is to have the desired effect. For example, the "read_data"_read_data.html command initializes the system by setting up the simulation box and assigning atoms to processors. If default values are not desired, the "processors"_processors.html and "boundary"_boundary.html commands need to be used before read_data to tell LAMMPS how to map processors to the simulation box. Many input script errors are detected by LAMMPS and an ERROR or WARNING message is printed. "This section"_Section_errors.html gives more information on what errors mean. The documentation for each command lists restrictions on how the command can be used. :line 3.2 Parsing rules :link(cmd_2),h4 Each non-blank line in the input script is treated as a command. LAMMPS commands are case sensitive. Command names are lower-case, as are specified command arguments. Upper case letters may be used in file names or user-chosen ID strings. Here is how each line in the input script is parsed by LAMMPS: (1) If the last printable character on the line is a "&" character, the command is assumed to continue on the next line. The next line is concatenated to the previous line by removing the "&" character and line break. This allows long commands to be continued across two or more lines. See the discussion of triple quotes in (6) for how to continue a command across multiple line without using "&" characters. (2) All characters from the first "#" character onward are treated as comment and discarded. See an exception in (6). Note that a comment after a trailing "&" character will prevent the command from continuing on the next line. Also note that for multi-line commands a single leading "#" will comment out the entire command. (3) The line is searched repeatedly for $ characters, which indicate variables that are replaced with a text string. See an exception in (6). If the $ is followed by curly brackets, then the variable name is the text inside the curly brackets. If no curly brackets follow the $, then the variable name is the single character immediately following the $. Thus $\{myTemp\} and $x refer to variable names "myTemp" and "x". How the variable is converted to a text string depends on what style of variable it is; see the "variable"_variable.html doc page for details. It can be a variable that stores multiple text strings, and return one of them. The returned text string can be multiple "words" (space separated) which will then be interpreted as multiple arguments in the input command. The variable can also store a numeric formula which will be evaluated and its numeric result returned as a string. As a special case, if the $ is followed by parenthesis, then the text inside the parenthesis is treated as an "immediate" variable and evaluated as an "equal-style variable"_variable.html. This is a way to use numeric formulas in an input script without having to assign them to variable names. For example, these 3 input script lines: variable X equal (xlo+xhi)/2+sqrt(v_area) region 1 block $X 2 INF INF EDGE EDGE variable X delete :pre can be replaced by region 1 block $((xlo+xhi)/2+sqrt(v_area)) 2 INF INF EDGE EDGE :pre so that you do not have to define (or discard) a temporary variable X. Note that neither the curly-bracket or immediate form of variables can contain nested $ characters for other variables to substitute for. Thus you cannot do this: variable a equal 2 variable b2 equal 4 print "B2 = $\{b$a\}" :pre Nor can you specify this $($x-1.0) for an immediate variable, but you could use $(v_x-1.0), since the latter is valid syntax for an "equal-style variable"_variable.html. See the "variable"_variable.html command for more details of how strings are assigned to variables and evaluated, and how they can be used in input script commands. (4) The line is broken into "words" separated by whitespace (tabs, spaces). Note that words can thus contain letters, digits, underscores, or punctuation characters. (5) The first word is the command name. All successive words in the line are arguments. (6) If you want text with spaces to be treated as a single argument, it can be enclosed in either single or double or triple quotes. A long single argument enclosed in single or double quotes can span multiple lines if the "&" character is used, as described above. When the lines are concatenated together (and the "&" characters and line breaks removed), the text will become a single line. If you want multiple lines of an argument to retain their line breaks, the text can be enclosed in triple quotes, in which case "&" characters are not needed. For example: print "Volume = $v" print 'Volume = $v' if "$\{steps\} > 1000" then quit variable a string "red green blue & purple orange cyan" print """ System volume = $v System temperature = $t """ :pre In each case, the single, double, or triple quotes are removed when the single argument they enclose is stored internally. See the "dump modify format"_dump_modify.html, "print"_print.html, "if"_if.html, and "python"_python.html commands for examples. A "#" or "$" character that is between quotes will not be treated as a comment indicator in (2) or substituted for as a variable in (3). NOTE: If the argument is itself a command that requires a quoted argument (e.g. using a "print"_print.html command as part of an "if"_if.html or "run every"_run.html command), then single, double, or triple quotes can be nested in the usual manner. See the doc pages for those commands for examples. Only one of level of nesting is allowed, but that should be sufficient for most use cases. :line 3.3 Input script structure :h4,link(cmd_3) This section describes the structure of a typical LAMMPS input script. The "examples" directory in the LAMMPS distribution contains many sample input scripts; the corresponding problems are discussed in "Section 7"_Section_example.html, and animated on the "LAMMPS WWW Site"_lws. A LAMMPS input script typically has 4 parts: Initialization Atom definition Settings Run a simulation :ol The last 2 parts can be repeated as many times as desired. I.e. run a simulation, change some settings, run some more, etc. Each of the 4 parts is now described in more detail. Remember that almost all the commands need only be used if a non-default value is desired. (1) Initialization Set parameters that need to be defined before atoms are created or read-in from a file. The relevant commands are "units"_units.html, "dimension"_dimension.html, "newton"_newton.html, "processors"_processors.html, "boundary"_boundary.html, "atom_style"_atom_style.html, "atom_modify"_atom_modify.html. If force-field parameters appear in the files that will be read, these commands tell LAMMPS what kinds of force fields are being used: "pair_style"_pair_style.html, "bond_style"_bond_style.html, "angle_style"_angle_style.html, "dihedral_style"_dihedral_style.html, "improper_style"_improper_style.html. (2) Atom definition There are 3 ways to define atoms in LAMMPS. Read them in from a data or restart file via the "read_data"_read_data.html or "read_restart"_read_restart.html commands. These files can contain molecular topology information. Or create atoms on a lattice (with no molecular topology), using these commands: "lattice"_lattice.html, "region"_region.html, "create_box"_create_box.html, "create_atoms"_create_atoms.html. The entire set of atoms can be duplicated to make a larger simulation using the "replicate"_replicate.html command. (3) Settings Once atoms and molecular topology are defined, a variety of settings can be specified: force field coefficients, simulation parameters, output options, etc. Force field coefficients are set by these commands (they can also be set in the read-in files): "pair_coeff"_pair_coeff.html, "bond_coeff"_bond_coeff.html, "angle_coeff"_angle_coeff.html, "dihedral_coeff"_dihedral_coeff.html, "improper_coeff"_improper_coeff.html, "kspace_style"_kspace_style.html, "dielectric"_dielectric.html, "special_bonds"_special_bonds.html. Various simulation parameters are set by these commands: "neighbor"_neighbor.html, "neigh_modify"_neigh_modify.html, "group"_group.html, "timestep"_timestep.html, "reset_timestep"_reset_timestep.html, "run_style"_run_style.html, "min_style"_min_style.html, "min_modify"_min_modify.html. Fixes impose a variety of boundary conditions, time integration, and diagnostic options. The "fix"_fix.html command comes in many flavors. Various computations can be specified for execution during a simulation using the "compute"_compute.html, "compute_modify"_compute_modify.html, and "variable"_variable.html commands. Output options are set by the "thermo"_thermo.html, "dump"_dump.html, and "restart"_restart.html commands. (4) Run a simulation A molecular dynamics simulation is run using the "run"_run.html command. Energy minimization (molecular statics) is performed using the "minimize"_minimize.html command. A parallel tempering (replica-exchange) simulation can be run using the "temper"_temper.html command. :line 3.4 Commands listed by category :link(cmd_4),h4 This section lists core LAMMPS commands, grouped by category. The "next section"_#cmd_5 lists all commands alphabetically. The next section also includes (long) lists of style options for entries that appear in the following categories as a single command (fix, compute, pair, etc). Commands that are added by user packages are not included in the categories here, but they are in the next section. Initialization: "newton"_newton.html, "package"_package.html, "processors"_processors.html, "suffix"_suffix.html, "units"_units.html Setup simulation box: "boundary"_boundary.html, "box"_box.html, "change_box"_change_box.html, "create_box"_create_box.html, "dimension"_dimension.html, "lattice"_lattice.html, "region"_region.html Setup atoms: "atom_modify"_atom_modify.html, "atom_style"_atom_style.html, "balance"_balance.html, "create_atoms"_create_atoms.html, "create_bonds"_create_bonds.html, "delete_atoms"_delete_atoms.html, "delete_bonds"_delete_bonds.html, "displace_atoms"_displace_atoms.html, "group"_group.html, "mass"_mass.html, "molecule"_molecule.html, "read_data"_read_data.html, "read_dump"_read_dump.html, "read_restart"_read_restart.html, "replicate"_replicate.html, "set"_set.html, "velocity"_velocity.html Force fields: "angle_coeff"_angle_coeff.html, "angle_style"_angle_style.html, "bond_coeff"_bond_coeff.html, "bond_style"_bond_style.html, "bond_write"_bond_write.html, "dielectric"_dielectric.html, "dihedral_coeff"_dihedral_coeff.html, "dihedral_style"_dihedral_style.html, "improper_coeff"_improper_coeff.html, "improper_style"_improper_style.html, "kspace_modify"_kspace_modify.html, "kspace_style"_kspace_style.html, "pair_coeff"_pair_coeff.html, "pair_modify"_pair_modify.html, "pair_style"_pair_style.html, "pair_write"_pair_write.html, "special_bonds"_special_bonds.html Settings: "comm_modify"_comm_modify.html, "comm_style"_comm_style.html, "info"_info.html, "min_modify"_min_modify.html, "min_style"_min_style.html, "neigh_modify"_neigh_modify.html, "neighbor"_neighbor.html, "partition"_partition.html, "reset_timestep"_reset_timestep.html, "run_style"_run_style.html, "timer"_timer.html, "timestep"_timestep.html Operations within timestepping (fixes) and diagnostics (computes): "compute"_compute.html, "compute_modify"_compute_modify.html, "fix"_fix.html, "fix_modify"_fix_modify.html, "uncompute"_uncompute.html, "unfix"_unfix.html Output: "dump image"_dump_image.html, "dump movie"_dump_image.html, "dump"_dump.html, "dump_modify"_dump_modify.html, "restart"_restart.html, "thermo"_thermo.html, "thermo_modify"_thermo_modify.html, "thermo_style"_thermo_style.html, "undump"_undump.html, "write_coeff"_write_coeff.html, "write_data"_write_data.html, "write_dump"_write_dump.html, "write_restart"_write_restart.html Actions: "minimize"_minimize.html, "neb"_neb.html, "prd"_prd.html, "rerun"_rerun.html, "run"_run.html, "tad"_tad.html, "temper"_temper.html Input script control: "clear"_clear.html, "echo"_echo.html, "if"_if.html, "include"_include.html, "jump"_jump.html, "label"_label.html, "log"_log.html, "next"_next.html, "print"_print.html, "python"_python.html, "quit"_quit.html, "shell"_shell.html, "variable"_variable.html :line 3.5 Individual commands :h4,link(cmd_5),link(comm) This section lists all LAMMPS commands alphabetically, with a separate listing below of styles within certain commands. The "previous section"_#cmd_4 lists the same commands, grouped by category. Note that some style options for some commands are part of specific LAMMPS packages, which means they cannot be used unless the package was included when LAMMPS was built. Not all packages are included in a default LAMMPS build. These dependencies are listed as Restrictions in the command's documentation. "angle_coeff"_angle_coeff.html, "angle_style"_angle_style.html, "atom_modify"_atom_modify.html, "atom_style"_atom_style.html, "balance"_balance.html, "bond_coeff"_bond_coeff.html, "bond_style"_bond_style.html, "bond_write"_bond_write.html, "boundary"_boundary.html, "box"_box.html, "change_box"_change_box.html, "clear"_clear.html, "comm_modify"_comm_modify.html, "comm_style"_comm_style.html, "compute"_compute.html, "compute_modify"_compute_modify.html, "create_atoms"_create_atoms.html, "create_bonds"_create_bonds.html, "create_box"_create_box.html, "delete_atoms"_delete_atoms.html, "delete_bonds"_delete_bonds.html, "dielectric"_dielectric.html, "dihedral_coeff"_dihedral_coeff.html, "dihedral_style"_dihedral_style.html, "dimension"_dimension.html, "displace_atoms"_displace_atoms.html, "dump"_dump.html, "dump image"_dump_image.html, "dump_modify"_dump_modify.html, "dump movie"_dump_image.html, "echo"_echo.html, "fix"_fix.html, "fix_modify"_fix_modify.html, "group"_group.html, "if"_if.html, "info"_info.html, "improper_coeff"_improper_coeff.html, "improper_style"_improper_style.html, "include"_include.html, "jump"_jump.html, "kspace_modify"_kspace_modify.html, "kspace_style"_kspace_style.html, "label"_label.html, "lattice"_lattice.html, "log"_log.html, "mass"_mass.html, "minimize"_minimize.html, "min_modify"_min_modify.html, "min_style"_min_style.html, "molecule"_molecule.html, "neb"_neb.html, "neigh_modify"_neigh_modify.html, "neighbor"_neighbor.html, "newton"_newton.html, "next"_next.html, "package"_package.html, "pair_coeff"_pair_coeff.html, "pair_modify"_pair_modify.html, "pair_style"_pair_style.html, "pair_write"_pair_write.html, "partition"_partition.html, "prd"_prd.html, "print"_print.html, "processors"_processors.html, "python"_python.html, "quit"_quit.html, "read_data"_read_data.html, "read_dump"_read_dump.html, "read_restart"_read_restart.html, "region"_region.html, "replicate"_replicate.html, "rerun"_rerun.html, "reset_timestep"_reset_timestep.html, "restart"_restart.html, "run"_run.html, "run_style"_run_style.html, "set"_set.html, "shell"_shell.html, "special_bonds"_special_bonds.html, "suffix"_suffix.html, "tad"_tad.html, "temper"_temper.html, "thermo"_thermo.html, "thermo_modify"_thermo_modify.html, "thermo_style"_thermo_style.html, "timer"_timer.html, "timestep"_timestep.html, "uncompute"_uncompute.html, "undump"_undump.html, "unfix"_unfix.html, "units"_units.html, "variable"_variable.html, "velocity"_velocity.html, "write_coeff"_write_coeff.html, "write_data"_write_data.html, "write_dump"_write_dump.html, "write_restart"_write_restart.html :tb(c=6,ea=c) These are additional commands in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "dump netcdf"_dump_netcdf.html, "dump netcdf/mpiio"_dump_netcdf.html, "dump vtk"_dump_vtk.html, "group2ndx"_group2ndx.html, "ndx2group"_group2ndx.html, "temper/grem"_temper_grem.html, "temper/npt"_temper_npt.html :tb(c=3,ea=c) :line Fix styles :h4 See the "fix"_fix.html command for one-line descriptions of each style or click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "adapt"_fix_adapt.html, "addforce"_fix_addforce.html, "append/atoms"_fix_append_atoms.html, "atom/swap"_fix_atom_swap.html, "aveforce"_fix_aveforce.html, "ave/atom"_fix_ave_atom.html, "ave/chunk"_fix_ave_chunk.html, "ave/correlate"_fix_ave_correlate.html, "ave/histo"_fix_ave_histo.html, "ave/histo/weight"_fix_ave_histo.html, "ave/time"_fix_ave_time.html, "balance"_fix_balance.html, "bond/break"_fix_bond_break.html, "bond/create"_fix_bond_create.html, "bond/swap"_fix_bond_swap.html, "box/relax"_fix_box_relax.html, "cmap"_fix_cmap.html, "controller"_fix_controller.html, "deform (k)"_fix_deform.html, "deposit"_fix_deposit.html, "drag"_fix_drag.html, "dt/reset"_fix_dt_reset.html, "efield"_fix_efield.html, "ehex"_fix_ehex.html, "enforce2d"_fix_enforce2d.html, "evaporate"_fix_evaporate.html, "external"_fix_external.html, "freeze"_fix_freeze.html, "gcmc"_fix_gcmc.html, "gld"_fix_gld.html, "gravity (o)"_fix_gravity.html, "halt"_fix_halt.html, "heat"_fix_heat.html, "indent"_fix_indent.html, +"latte"_fix_latte.html, "langevin (k)"_fix_langevin.html, "lineforce"_fix_lineforce.html, "momentum (k)"_fix_momentum.html, "move"_fix_move.html, "mscg"_fix_mscg.html, "msst"_fix_msst.html, "neb"_fix_neb.html, "nph (ko)"_fix_nh.html, "nphug (o)"_fix_nphug.html, "nph/asphere (o)"_fix_nph_asphere.html, "nph/body"_fix_nph_body.html, "nph/sphere (o)"_fix_nph_sphere.html, "npt (kio)"_fix_nh.html, "npt/asphere (o)"_fix_npt_asphere.html, "npt/body"_fix_npt_body.html, "npt/sphere (o)"_fix_npt_sphere.html, "nve (kio)"_fix_nve.html, "nve/asphere (i)"_fix_nve_asphere.html, "nve/asphere/noforce"_fix_nve_asphere_noforce.html, "nve/body"_fix_nve_body.html, "nve/limit"_fix_nve_limit.html, "nve/line"_fix_nve_line.html, "nve/noforce"_fix_nve_noforce.html, "nve/sphere (o)"_fix_nve_sphere.html, "nve/tri"_fix_nve_tri.html, "nvt (iko)"_fix_nh.html, "nvt/asphere (o)"_fix_nvt_asphere.html, "nvt/body"_fix_nvt_body.html, "nvt/sllod (io)"_fix_nvt_sllod.html, "nvt/sphere (o)"_fix_nvt_sphere.html, "oneway"_fix_oneway.html, "orient/bcc"_fix_orient.html, "orient/fcc"_fix_orient.html, "planeforce"_fix_planeforce.html, "poems"_fix_poems.html, "pour"_fix_pour.html, "press/berendsen"_fix_press_berendsen.html, "print"_fix_print.html, "property/atom"_fix_property_atom.html, "python"_fix_python.html, "qeq/comb (o)"_fix_qeq_comb.html, "qeq/dynamic"_fix_qeq.html, "qeq/fire"_fix_qeq.html, "qeq/point"_fix_qeq.html, "qeq/shielded"_fix_qeq.html, "qeq/slater"_fix_qeq.html, "rattle"_fix_shake.html, "reax/bonds"_fix_reax_bonds.html, "recenter"_fix_recenter.html, "restrain"_fix_restrain.html, "rigid (o)"_fix_rigid.html, "rigid/nph (o)"_fix_rigid.html, "rigid/npt (o)"_fix_rigid.html, "rigid/nve (o)"_fix_rigid.html, "rigid/nvt (o)"_fix_rigid.html, "rigid/small (o)"_fix_rigid.html, "rigid/small/nph (o)"_fix_rigid.html, "rigid/small/npt (o)"_fix_rigid.html, "rigid/small/nve (o)"_fix_rigid.html, "rigid/small/nvt (o)"_fix_rigid.html, "setforce (k)"_fix_setforce.html, "shake"_fix_shake.html, "spring"_fix_spring.html, "spring/chunk"_fix_spring_chunk.html, "spring/rg"_fix_spring_rg.html, "spring/self"_fix_spring_self.html, "srd"_fix_srd.html, "store/force"_fix_store_force.html, "store/state"_fix_store_state.html, "temp/berendsen"_fix_temp_berendsen.html, "temp/csld"_fix_temp_csvr.html, "temp/csvr"_fix_temp_csvr.html, "temp/rescale"_fix_temp_rescale.html, "tfmc"_fix_tfmc.html, "thermal/conductivity"_fix_thermal_conductivity.html, "tmd"_fix_tmd.html, "ttm"_fix_ttm.html, "tune/kspace"_fix_tune_kspace.html, "vector"_fix_vector.html, "viscosity"_fix_viscosity.html, "viscous"_fix_viscous.html, "wall/colloid"_fix_wall.html, "wall/gran"_fix_wall_gran.html, "wall/gran/region"_fix_wall_gran_region.html, "wall/harmonic"_fix_wall.html, "wall/lj1043"_fix_wall.html, "wall/lj126"_fix_wall.html, "wall/lj93"_fix_wall.html, "wall/piston"_fix_wall_piston.html, "wall/reflect (k)"_fix_wall_reflect.html, "wall/region"_fix_wall_region.html, "wall/srd"_fix_wall_srd.html :tb(c=8,ea=c) These are additional fix styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "adapt/fep"_fix_adapt_fep.html, "addtorque"_fix_addtorque.html, "atc"_fix_atc.html, "ave/correlate/long"_fix_ave_correlate_long.html, "colvars"_fix_colvars.html, "dpd/energy"_fix_dpd_energy.html, "drude"_fix_drude.html, "drude/transform/direct"_fix_drude_transform.html, "drude/transform/reverse"_fix_drude_transform.html, "edpd/source"_fix_dpd_source.html, "eos/cv"_fix_eos_cv.html, "eos/table"_fix_eos_table.html, "eos/table/rx"_fix_eos_table_rx.html, "filter/corotate"_fix_filter_corotate.html, "flow/gauss"_fix_flow_gauss.html, "gle"_fix_gle.html, "grem"_fix_grem.html, "imd"_fix_imd.html, "ipi"_fix_ipi.html, "langevin/drude"_fix_langevin_drude.html, "langevin/eff"_fix_langevin_eff.html, "lb/fluid"_fix_lb_fluid.html, "lb/momentum"_fix_lb_momentum.html, "lb/pc"_fix_lb_pc.html, "lb/rigid/pc/sphere"_fix_lb_rigid_pc_sphere.html, "lb/viscous"_fix_lb_viscous.html, "meso"_fix_meso.html, "manifoldforce"_fix_manifoldforce.html, "meso/stationary"_fix_meso_stationary.html, "mvv/dpd"_fix_mvv_dpd.html, "mvv/edpd"_fix_mvv_dpd.html, "mvv/tdpd"_fix_mvv_dpd.html, "nve/dot"_fix_nve_dot.html, "nve/dotc/langevin"_fix_nve_dotc_langevin.html, "nve/manifold/rattle"_fix_nve_manifold_rattle.html, "nvk"_fix_nvk.html, "nvt/manifold/rattle"_fix_nvt_manifold_rattle.html, "nph/eff"_fix_nh_eff.html, "npt/eff"_fix_nh_eff.html, "nve/eff"_fix_nve_eff.html, "nvt/eff"_fix_nh_eff.html, "nvt/sllod/eff"_fix_nvt_sllod_eff.html, "phonon"_fix_phonon.html, "pimd"_fix_pimd.html, "qbmsst"_fix_qbmsst.html, "qeq/reax (ko)"_fix_qeq_reax.html, "qmmm"_fix_qmmm.html, "qtb"_fix_qtb.html, "reax/c/bonds"_fix_reax_bonds.html, "reax/c/species"_fix_reaxc_species.html, "rx"_fix_rx.html, "saed/vtk"_fix_saed_vtk.html, "shardlow"_fix_shardlow.html, "smd"_fix_smd.html, "smd/adjust/dt"_fix_smd_adjust_dt.html, "smd/integrate/tlsph"_fix_smd_integrate_tlsph.html, "smd/integrate/ulsph"_fix_smd_integrate_ulsph.html, "smd/move/triangulated/surface"_fix_smd_move_triangulated_surface.html, "smd/setvel"_fix_smd_setvel.html, "smd/wall/surface"_fix_smd_wall_surface.html, "tdpd/source"_fix_dpd_source.html, "temp/rescale/eff"_fix_temp_rescale_eff.html, "ti/spring"_fix_ti_spring.html, "ttm/mod"_fix_ttm.html, "wall/ees"_fix_wall_ees.html, "wall/region/ees"_fix_wall_ees.html :tb(c=6,ea=c) :line Compute styles :h4 See the "compute"_compute.html command for one-line descriptions of each style or click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "aggregate/atom"_compute_cluster_atom.html, "angle"_compute_angle.html, "angle/local"_compute_angle_local.html, "angmom/chunk"_compute_angmom_chunk.html, "body/local"_compute_body_local.html, "bond"_compute_bond.html, "bond/local"_compute_bond_local.html, "centro/atom"_compute_centro_atom.html, "chunk/atom"_compute_chunk_atom.html, "cluster/atom"_compute_cluster_atom.html, "cna/atom"_compute_cna_atom.html, "com"_compute_com.html, "com/chunk"_compute_com_chunk.html, "contact/atom"_compute_contact_atom.html, "coord/atom"_compute_coord_atom.html, "damage/atom"_compute_damage_atom.html, "dihedral"_compute_dihedral.html, "dihedral/local"_compute_dihedral_local.html, "dilatation/atom"_compute_dilatation_atom.html, "dipole/chunk"_compute_dipole_chunk.html, "displace/atom"_compute_displace_atom.html, "erotate/asphere"_compute_erotate_asphere.html, "erotate/rigid"_compute_erotate_rigid.html, "erotate/sphere"_compute_erotate_sphere.html, "erotate/sphere/atom"_compute_erotate_sphere_atom.html, "event/displace"_compute_event_displace.html, "fragment/atom"_compute_cluster_atom.html, "global/atom"_compute_global_atom.html, "group/group"_compute_group_group.html, "gyration"_compute_gyration.html, "gyration/chunk"_compute_gyration_chunk.html, "heat/flux"_compute_heat_flux.html, "hexorder/atom"_compute_hexorder_atom.html, "improper"_compute_improper.html, "improper/local"_compute_improper_local.html, "inertia/chunk"_compute_inertia_chunk.html, "ke"_compute_ke.html, "ke/atom"_compute_ke_atom.html, "ke/rigid"_compute_ke_rigid.html, "msd"_compute_msd.html, "msd/chunk"_compute_msd_chunk.html, "msd/nongauss"_compute_msd_nongauss.html, "omega/chunk"_compute_omega_chunk.html, "orientorder/atom"_compute_orientorder_atom.html, "pair"_compute_pair.html, "pair/local"_compute_pair_local.html, "pe"_compute_pe.html, "pe/atom"_compute_pe_atom.html, "plasticity/atom"_compute_plasticity_atom.html, "pressure"_compute_pressure.html, "property/atom"_compute_property_atom.html, "property/local"_compute_property_local.html, "property/chunk"_compute_property_chunk.html, "rdf"_compute_rdf.html, "reduce"_compute_reduce.html, "reduce/region"_compute_reduce.html, "rigid/local"_compute_rigid_local.html, "slice"_compute_slice.html, "sna/atom"_compute_sna_atom.html, "snad/atom"_compute_sna_atom.html, "snav/atom"_compute_sna_atom.html, "stress/atom"_compute_stress_atom.html, "temp (k)"_compute_temp.html, "temp/asphere"_compute_temp_asphere.html, "temp/body"_compute_temp_body.html, "temp/chunk"_compute_temp_chunk.html, "temp/com"_compute_temp_com.html, "temp/deform"_compute_temp_deform.html, "temp/partial"_compute_temp_partial.html, "temp/profile"_compute_temp_profile.html, "temp/ramp"_compute_temp_ramp.html, "temp/region"_compute_temp_region.html, "temp/sphere"_compute_temp_sphere.html, "ti"_compute_ti.html, "torque/chunk"_compute_torque_chunk.html, "vacf"_compute_vacf.html, "vcm/chunk"_compute_vcm_chunk.html, "voronoi/atom"_compute_voronoi_atom.html :tb(c=6,ea=c) These are additional compute styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "ackland/atom"_compute_ackland_atom.html, "basal/atom"_compute_basal_atom.html, "cnp/atom"_compute_cnp_atom.html, "dpd"_compute_dpd.html, "dpd/atom"_compute_dpd_atom.html, "edpd/temp/atom"_compute_edpd_temp_atom.html, "fep"_compute_fep.html, "force/tally"_compute_tally.html, "heat/flux/tally"_compute_tally.html, "ke/eff"_compute_ke_eff.html, "ke/atom/eff"_compute_ke_atom_eff.html, "meso/e/atom"_compute_meso_e_atom.html, "meso/rho/atom"_compute_meso_rho_atom.html, "meso/t/atom"_compute_meso_t_atom.html, "pe/tally"_compute_tally.html, "pe/mol/tally"_compute_tally.html, "saed"_compute_saed.html, "smd/contact/radius"_compute_smd_contact_radius.html, "smd/damage"_compute_smd_damage.html, "smd/hourglass/error"_compute_smd_hourglass_error.html, "smd/internal/energy"_compute_smd_internal_energy.html, "smd/plastic/strain"_compute_smd_plastic_strain.html, "smd/plastic/strain/rate"_compute_smd_plastic_strain_rate.html, "smd/rho"_compute_smd_rho.html, "smd/tlsph/defgrad"_compute_smd_tlsph_defgrad.html, "smd/tlsph/dt"_compute_smd_tlsph_dt.html, "smd/tlsph/num/neighs"_compute_smd_tlsph_num_neighs.html, "smd/tlsph/shape"_compute_smd_tlsph_shape.html, "smd/tlsph/strain"_compute_smd_tlsph_strain.html, "smd/tlsph/strain/rate"_compute_smd_tlsph_strain_rate.html, "smd/tlsph/stress"_compute_smd_tlsph_stress.html, "smd/triangle/mesh/vertices"_compute_smd_triangle_mesh_vertices.html, "smd/ulsph/num/neighs"_compute_smd_ulsph_num_neighs.html, "smd/ulsph/strain"_compute_smd_ulsph_strain.html, "smd/ulsph/strain/rate"_compute_smd_ulsph_strain_rate.html, "smd/ulsph/stress"_compute_smd_ulsph_stress.html, "smd/vol"_compute_smd_vol.html, "stress/tally"_compute_tally.html, "tdpd/cc/atom"_compute_tdpd_cc_atom.html, "temp/drude"_compute_temp_drude.html, "temp/eff"_compute_temp_eff.html, "temp/deform/eff"_compute_temp_deform_eff.html, "temp/region/eff"_compute_temp_region_eff.html, "temp/rotate"_compute_temp_rotate.html, "xrd"_compute_xrd.html :tb(c=6,ea=c) :line Pair_style potentials :h4 See the "pair_style"_pair_style.html command for an overview of pair potentials. Click on the style itself for a full description. Many of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "none"_pair_none.html, "zero"_pair_zero.html, "hybrid"_pair_hybrid.html, "hybrid/overlay"_pair_hybrid.html, "adp (o)"_pair_adp.html, "airebo (oi)"_pair_airebo.html, "airebo/morse (oi)"_pair_airebo.html, "beck (go)"_pair_beck.html, "body"_pair_body.html, "bop"_pair_bop.html, "born (go)"_pair_born.html, "born/coul/dsf"_pair_born.html, "born/coul/dsf/cs"_pair_born.html, "born/coul/long (go)"_pair_born.html, "born/coul/long/cs"_pair_born.html, "born/coul/msm (o)"_pair_born.html, "born/coul/wolf (go)"_pair_born.html, "brownian (o)"_pair_brownian.html, "brownian/poly (o)"_pair_brownian.html, "buck (gkio)"_pair_buck.html, "buck/coul/cut (gkio)"_pair_buck.html, "buck/coul/long (gkio)"_pair_buck.html, "buck/coul/long/cs"_pair_buck.html, "buck/coul/msm (o)"_pair_buck.html, "buck/long/coul/long (o)"_pair_buck_long.html, "colloid (go)"_pair_colloid.html, "comb (o)"_pair_comb.html, "comb3"_pair_comb.html, "coul/cut (gko)"_pair_coul.html, "coul/debye (gko)"_pair_coul.html, "coul/dsf (gko)"_pair_coul.html, "coul/long (gko)"_pair_coul.html, "coul/long/cs"_pair_coul.html, "coul/msm"_pair_coul.html, "coul/streitz"_pair_coul.html, "coul/wolf (ko)"_pair_coul.html, "dpd (go)"_pair_dpd.html, "dpd/tstat (go)"_pair_dpd.html, "dsmc"_pair_dsmc.html, "eam (gkiot)"_pair_eam.html, "eam/alloy (gkiot)"_pair_eam.html, "eam/fs (gkiot)"_pair_eam.html, "eim (o)"_pair_eim.html, "gauss (go)"_pair_gauss.html, "gayberne (gio)"_pair_gayberne.html, "gran/hertz/history (o)"_pair_gran.html, "gran/hooke (o)"_pair_gran.html, "gran/hooke/history (o)"_pair_gran.html, "gw"_pair_gw.html, "gw/zbl"_pair_gw.html, "hbond/dreiding/lj (o)"_pair_hbond_dreiding.html, "hbond/dreiding/morse (o)"_pair_hbond_dreiding.html, "kim"_pair_kim.html, "lcbop"_pair_lcbop.html, "line/lj"_pair_line_lj.html, "lj/charmm/coul/charmm (kio)"_pair_charmm.html, "lj/charmm/coul/charmm/implicit (ko)"_pair_charmm.html, "lj/charmm/coul/long (gkio)"_pair_charmm.html, "lj/charmm/coul/msm"_pair_charmm.html, "lj/charmmfsw/coul/charmmfsh"_pair_charmm.html, "lj/charmmfsw/coul/long"_pair_charmm.html, "lj/class2 (gko)"_pair_class2.html, "lj/class2/coul/cut (ko)"_pair_class2.html, "lj/class2/coul/long (gko)"_pair_class2.html, "lj/cubic (go)"_pair_lj_cubic.html, "lj/cut (gikot)"_pair_lj.html, "lj/cut/coul/cut (gko)"_pair_lj.html, "lj/cut/coul/debye (gko)"_pair_lj.html, "lj/cut/coul/dsf (gko)"_pair_lj.html, "lj/cut/coul/long (gikot)"_pair_lj.html, "lj/cut/coul/long/cs"_pair_lj.html, "lj/cut/coul/msm (go)"_pair_lj.html, "lj/cut/dipole/cut (go)"_pair_dipole.html, "lj/cut/dipole/long"_pair_dipole.html, "lj/cut/tip4p/cut (o)"_pair_lj.html, "lj/cut/tip4p/long (ot)"_pair_lj.html, "lj/expand (gko)"_pair_lj_expand.html, "lj/gromacs (gko)"_pair_gromacs.html, "lj/gromacs/coul/gromacs (ko)"_pair_gromacs.html, "lj/long/coul/long (io)"_pair_lj_long.html, "lj/long/dipole/long"_pair_dipole.html, "lj/long/tip4p/long"_pair_lj_long.html, "lj/smooth (o)"_pair_lj_smooth.html, "lj/smooth/linear (o)"_pair_lj_smooth_linear.html, "lj96/cut (go)"_pair_lj96.html, "lubricate (o)"_pair_lubricate.html, "lubricate/poly (o)"_pair_lubricate.html, "lubricateU"_pair_lubricateU.html, "lubricateU/poly"_pair_lubricateU.html, "meam"_pair_meam.html, "mie/cut (o)"_pair_mie.html, "morse (gkot)"_pair_morse.html, "nb3b/harmonic (o)"_pair_nb3b_harmonic.html, "nm/cut (o)"_pair_nm.html, "nm/cut/coul/cut (o)"_pair_nm.html, "nm/cut/coul/long (o)"_pair_nm.html, "peri/eps"_pair_peri.html, "peri/lps (o)"_pair_peri.html, "peri/pmb (o)"_pair_peri.html, "peri/ves"_pair_peri.html, "polymorphic"_pair_polymorphic.html, "python"_pair_python.html, "reax"_pair_reax.html, "rebo (oi)"_pair_airebo.html, "resquared (go)"_pair_resquared.html, "snap"_pair_snap.html, "soft (go)"_pair_soft.html, "sw (gkio)"_pair_sw.html, "table (gko)"_pair_table.html, "tersoff (gkio)"_pair_tersoff.html, "tersoff/mod (gko)"_pair_tersoff_mod.html, "tersoff/mod/c (o)"_pair_tersoff_mod.html, "tersoff/zbl (gko)"_pair_tersoff_zbl.html, "tip4p/cut (o)"_pair_coul.html, "tip4p/long (o)"_pair_coul.html, "tri/lj"_pair_tri_lj.html, "vashishta (ko)"_pair_vashishta.html, "vashishta/table (o)"_pair_vashishta.html, "yukawa (go)"_pair_yukawa.html, "yukawa/colloid (go)"_pair_yukawa_colloid.html, "zbl (go)"_pair_zbl.html :tb(c=4,ea=c) These are additional pair styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "agni (o)"_pair_agni.html, "awpmd/cut"_pair_awpmd.html, "buck/mdf"_pair_mdf.html, "coul/cut/soft (o)"_pair_lj_soft.html, "coul/diel (o)"_pair_coul_diel.html, "coul/long/soft (o)"_pair_lj_soft.html, "dpd/fdt"_pair_dpd_fdt.html, "dpd/fdt/energy"_pair_dpd_fdt.html, "eam/cd (o)"_pair_eam.html, "edip (o)"_pair_edip.html, "edip/multi"_pair_edip.html, "edpd"_pair_meso.html, "eff/cut"_pair_eff.html, "exp6/rx"_pair_exp6_rx.html, "gauss/cut"_pair_gauss.html, "kolmogorov/crespi/z"_pair_kolmogorov_crespi_z.html, "lennard/mdf"_pair_mdf.html, "list"_pair_list.html, "lj/charmm/coul/long/soft (o)"_pair_charmm.html, "lj/cut/coul/cut/soft (o)"_pair_lj_soft.html, "lj/cut/coul/long/soft (o)"_pair_lj_soft.html, "lj/cut/dipole/sf (go)"_pair_dipole.html, "lj/cut/soft (o)"_pair_lj_soft.html, "lj/cut/thole/long (o)"_pair_thole.html, "lj/cut/tip4p/long/soft (o)"_pair_lj_soft.html, "lj/mdf"_pair_mdf.html, "lj/sdk (gko)"_pair_sdk.html, "lj/sdk/coul/long (go)"_pair_sdk.html, "lj/sdk/coul/msm (o)"_pair_sdk.html, "mdpd"_pair_meso.html, "mdpd/rhosum"_pair_meso.html, "meam/c"_pair_meam.html, "meam/spline (o)"_pair_meam_spline.html, "meam/sw/spline"_pair_meam_sw_spline.html, "mgpt"_pair_mgpt.html, "momb"_pair_momb.html, "morse/smooth/linear"_pair_morse.html, "morse/soft"_pair_morse.html, "multi/lucy"_pair_multi_lucy.html, "multi/lucy/rx"_pair_multi_lucy_rx.html, "oxdna/coaxstk"_pair_oxdna.html, "oxdna/excv"_pair_oxdna.html, "oxdna/hbond"_pair_oxdna.html, "oxdna/stk"_pair_oxdna.html, "oxdna/xstk"_pair_oxdna.html, "oxdna2/coaxstk"_pair_oxdna2.html, "oxdna2/dh"_pair_oxdna2.html, "oxdna2/excv"_pair_oxdna2.html, "oxdna2/stk"_pair_oxdna2.html, "quip"_pair_quip.html, "reax/c (ko)"_pair_reaxc.html, "smd/hertz"_pair_smd_hertz.html, "smd/tlsph"_pair_smd_tlsph.html, "smd/triangulated/surface"_pair_smd_triangulated_surface.html, "smd/ulsph"_pair_smd_ulsph.html, "smtbq"_pair_smtbq.html, "sph/heatconduction"_pair_sph_heatconduction.html, "sph/idealgas"_pair_sph_idealgas.html, "sph/lj"_pair_sph_lj.html, "sph/rhosum"_pair_sph_rhosum.html, "sph/taitwater"_pair_sph_taitwater.html, "sph/taitwater/morris"_pair_sph_taitwater_morris.html, "srp"_pair_srp.html, "table/rx"_pair_table_rx.html, "tdpd"_pair_meso.html, "tersoff/table (o)"_pair_tersoff.html, "thole"_pair_thole.html, "tip4p/long/soft (o)"_pair_lj_soft.html :tb(c=4,ea=c) :line Bond_style potentials :h4 See the "bond_style"_bond_style.html command for an overview of bond potentials. Click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "none"_bond_none.html, "zero"_bond_zero.html, "hybrid"_bond_hybrid.html, "class2 (ko)"_bond_class2.html, "fene (iko)"_bond_fene.html, "fene/expand (o)"_bond_fene_expand.html, "harmonic (ko)"_bond_harmonic.html, "morse (o)"_bond_morse.html, "nonlinear (o)"_bond_nonlinear.html, "quartic (o)"_bond_quartic.html, "table (o)"_bond_table.html :tb(c=4,ea=c) These are additional bond styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "harmonic/shift (o)"_bond_harmonic_shift.html, "harmonic/shift/cut (o)"_bond_harmonic_shift_cut.html, "oxdna/fene"_bond_oxdna.html, "oxdna2/fene"_bond_oxdna.html :tb(c=4,ea=c) :line Angle_style potentials :h4 See the "angle_style"_angle_style.html command for an overview of angle potentials. Click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "none"_angle_none.html, "zero"_angle_zero.html, "hybrid"_angle_hybrid.html, "charmm (ko)"_angle_charmm.html, "class2 (ko)"_angle_class2.html, "cosine (o)"_angle_cosine.html, "cosine/delta (o)"_angle_cosine_delta.html, "cosine/periodic (o)"_angle_cosine_periodic.html, "cosine/squared (o)"_angle_cosine_squared.html, "harmonic (iko)"_angle_harmonic.html, "table (o)"_angle_table.html :tb(c=4,ea=c) These are additional angle styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "cosine/shift (o)"_angle_cosine_shift.html, "cosine/shift/exp (o)"_angle_cosine_shift_exp.html, "dipole (o)"_angle_dipole.html, "fourier (o)"_angle_fourier.html, "fourier/simple (o)"_angle_fourier_simple.html, "quartic (o)"_angle_quartic.html, "sdk"_angle_sdk.html :tb(c=4,ea=c) :line Dihedral_style potentials :h4 See the "dihedral_style"_dihedral_style.html command for an overview of dihedral potentials. Click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "none"_dihedral_none.html, "zero"_dihedral_zero.html, "hybrid"_dihedral_hybrid.html, "charmm (ko)"_dihedral_charmm.html, "charmmfsw"_dihedral_charmm.html, "class2 (ko)"_dihedral_class2.html, "harmonic (io)"_dihedral_harmonic.html, "helix (o)"_dihedral_helix.html, "multi/harmonic (o)"_dihedral_multi_harmonic.html, "opls (iko)"_dihedral_opls.html :tb(c=4,ea=c) These are additional dihedral styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "cosine/shift/exp (o)"_dihedral_cosine_shift_exp.html, "fourier (o)"_dihedral_fourier.html, "nharmonic (o)"_dihedral_nharmonic.html, "quadratic (o)"_dihedral_quadratic.html, "spherical (o)"_dihedral_spherical.html, "table (o)"_dihedral_table.html :tb(c=4,ea=c) :line Improper_style potentials :h4 See the "improper_style"_improper_style.html command for an overview of improper potentials. Click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "none"_improper_none.html, "zero"_improper_zero.html, "hybrid"_improper_hybrid.html, "class2 (ko)"_improper_class2.html, "cvff (io)"_improper_cvff.html, "harmonic (ko)"_improper_harmonic.html, "umbrella (o)"_improper_umbrella.html :tb(c=4,ea=c) These are additional improper styles in USER packages, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#start_3. "cossq (o)"_improper_cossq.html, "distance"_improper_distance.html, "fourier (o)"_improper_fourier.html, "ring (o)"_improper_ring.html :tb(c=4,ea=c) :line Kspace solvers :h4 See the "kspace_style"_kspace_style.html command for an overview of Kspace solvers. Click on the style itself for a full description. Some of the styles have accelerated versions, which can be used if LAMMPS is built with the "appropriate accelerated package"_Section_accelerate.html. This is indicated by additional letters in parenthesis: g = GPU, i = USER-INTEL, k = KOKKOS, o = USER-OMP, t = OPT. "ewald (o)"_kspace_style.html, "ewald/disp"_kspace_style.html, "msm (o)"_kspace_style.html, "msm/cg (o)"_kspace_style.html, "pppm (go)"_kspace_style.html, "pppm/cg (o)"_kspace_style.html, "pppm/disp (i)"_kspace_style.html, "pppm/disp/tip4p"_kspace_style.html, "pppm/stagger"_kspace_style.html, "pppm/tip4p (o)"_kspace_style.html :tb(c=4,ea=c) diff --git a/doc/src/fix.txt b/doc/src/fix.txt index 464eab316..e54a918cd 100644 --- a/doc/src/fix.txt +++ b/doc/src/fix.txt @@ -1,315 +1,316 @@ "LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c :link(lws,http://lammps.sandia.gov) :link(ld,Manual.html) :link(lc,Section_commands.html#comm) :line fix command :h3 [Syntax:] fix ID group-ID style args :pre ID = user-assigned name for the fix group-ID = ID of the group of atoms to apply the fix to style = one of a long list of possible style names (see below) args = arguments used by a particular style :ul [Examples:] fix 1 all nve fix 3 all nvt temp 300.0 300.0 0.01 fix mine top setforce 0.0 NULL 0.0 :pre [Description:] Set a fix that will be applied to a group of atoms. In LAMMPS, a "fix" is any operation that is applied to the system during timestepping or minimization. Examples include updating of atom positions and velocities due to time integration, controlling temperature, applying constraint forces to atoms, enforcing boundary conditions, computing diagnostics, etc. There are dozens of fixes defined in LAMMPS and new ones can be added; see "this section"_Section_modify.html for a discussion. Fixes perform their operations at different stages of the timestep. If 2 or more fixes operate at the same stage of the timestep, they are invoked in the order they were specified in the input script. The ID of a fix can only contain alphanumeric characters and underscores. Fixes can be deleted with the "unfix"_unfix.html command. NOTE: The "unfix"_unfix.html command is the only way to turn off a fix; simply specifying a new fix with a similar style will not turn off the first one. This is especially important to realize for integration fixes. For example, using a "fix nve"_fix_nve.html command for a second run after using a "fix nvt"_fix_nh.html command for the first run, will not cancel out the NVT time integration invoked by the "fix nvt" command. Thus two time integrators would be in place! If you specify a new fix with the same ID and style as an existing fix, the old fix is deleted and the new one is created (presumably with new settings). This is the same as if an "unfix" command were first performed on the old fix, except that the new fix is kept in the same order relative to the existing fixes as the old one originally was. Note that this operation also wipes out any additional changes made to the old fix via the "fix_modify"_fix_modify.html command. The "fix modify"_fix_modify.html command allows settings for some fixes to be reset. See the doc page for individual fixes for details. Some fixes store an internal "state" which is written to binary restart files via the "restart"_restart.html or "write_restart"_write_restart.html commands. This allows the fix to continue on with its calculations in a restarted simulation. See the "read_restart"_read_restart.html command for info on how to re-specify a fix in an input script that reads a restart file. See the doc pages for individual fixes for info on which ones can be restarted. :line Some fixes calculate one of three styles of quantities: global, per-atom, or local, which can be used by other commands or output as described below. A global quantity is one or more system-wide values, e.g. the energy of a wall interacting with particles. A per-atom quantity is one or more values per atom, e.g. the displacement vector for each atom since time 0. Per-atom values are set to 0.0 for atoms not in the specified fix group. Local quantities are calculated by each processor based on the atoms it owns, but there may be zero or more per atoms. Note that a single fix may produces either global or per-atom or local quantities (or none at all), but never more than one of these. Global, per-atom, and local quantities each come in three kinds: a single scalar value, a vector of values, or a 2d array of values. The doc page for each fix describes the style and kind of values it produces, e.g. a per-atom vector. Some fixes produce more than one kind of a single style, e.g. a global scalar and a global vector. When a fix quantity is accessed, as in many of the output commands discussed below, it can be referenced via the following bracket notation, where ID is the ID of the fix: f_ID | entire scalar, vector, or array f_ID\[I\] | one element of vector, one column of array f_ID\[I\]\[J\] | one element of array :tb(s=|) In other words, using one bracket reduces the dimension of the quantity once (vector -> scalar, array -> vector). Using two brackets reduces the dimension twice (array -> scalar). Thus a command that uses scalar fix values as input can also process elements of a vector or array. Note that commands and "variables"_variable.html which use fix quantities typically do not allow for all kinds, e.g. a command may require a vector of values, not a scalar. This means there is no ambiguity about referring to a fix quantity as f_ID even if it produces, for example, both a scalar and vector. The doc pages for various commands explain the details. :line In LAMMPS, the values generated by a fix can be used in several ways: Global values can be output via the "thermo_style custom"_thermo_style.html or "fix ave/time"_fix_ave_time.html command. Or the values can be referenced in a "variable equal"_variable.html or "variable atom"_variable.html command. :ulb,l Per-atom values can be output via the "dump custom"_dump.html command. Or they can be time-averaged via the "fix ave/atom"_fix_ave_atom.html command or reduced by the "compute reduce"_compute_reduce.html command. Or the per-atom values can be referenced in an "atom-style variable"_variable.html. :l Local values can be reduced by the "compute reduce"_compute_reduce.html command, or histogrammed by the "fix ave/histo"_fix_ave_histo.html command. :l :ule See this "howto section"_Section_howto.html#howto_15 for a summary of various LAMMPS output options, many of which involve fixes. The results of fixes that calculate global quantities can be either "intensive" or "extensive" values. Intensive means the value is independent of the number of atoms in the simulation, e.g. temperature. Extensive means the value scales with the number of atoms in the simulation, e.g. total rotational kinetic energy. "Thermodynamic output"_thermo_style.html will normalize extensive values by the number of atoms in the system, depending on the "thermo_modify norm" setting. It will not normalize intensive values. If a fix value is accessed in another way, e.g. by a "variable"_variable.html, you may want to know whether it is an intensive or extensive value. See the doc page for individual fixes for further info. :line Each fix style has its own documentation page which describes its arguments and what it does, as listed below. Here is an alphabetic list of fix styles available in LAMMPS. They are also given in more compact form in the Fix section of "this page"_Section_commands.html#cmd_5. There are also additional fix styles (not listed here) submitted by users which are included in the LAMMPS distribution. The list of these with links to the individual styles are given in the fix section of "this page"_Section_commands.html#cmd_5. "adapt"_fix_adapt.html - change a simulation parameter over time "addforce"_fix_addforce.html - add a force to each atom "append/atoms"_fix_append_atoms.html - append atoms to a running simulation "atom/swap"_fix_atom_swap.html - Monte Carlo atom type swapping "aveforce"_fix_aveforce.html - add an averaged force to each atom "ave/atom"_fix_ave_atom.html - compute per-atom time-averaged quantities "ave/chunk"_fix_ave_chunk.html - compute per-chunk time-averaged quantities "ave/correlate"_fix_ave_correlate.html - compute/output time correlations "ave/histo"_fix_ave_histo.html - compute/output time-averaged histograms "ave/time"_fix_ave_time.html - compute/output global time-averaged quantities "balance"_fix_balance.html - perform dynamic load-balancing "bond/break"_fix_bond_break.html - break bonds on the fly "bond/create"_fix_bond_create.html - create bonds on the fly "bond/swap"_fix_bond_swap.html - Monte Carlo bond swapping "box/relax"_fix_box_relax.html - relax box size during energy minimization "deform"_fix_deform.html - change the simulation box size/shape "deposit"_fix_deposit.html - add new atoms above a surface "drag"_fix_drag.html - drag atoms towards a defined coordinate "dt/reset"_fix_dt_reset.html - reset the timestep based on velocity, forces "efield"_fix_efield.html - impose electric field on system "ehex"_fix_ehex.html - ehanced heat exchange algorithm "enforce2d"_fix_enforce2d.html - zero out z-dimension velocity and force "evaporate"_fix_evaporate.html - remove atoms from simulation periodically "external"_fix_external.html - callback to an external driver program "freeze"_fix_freeze.html - freeze atoms in a granular simulation "gcmc"_fix_gcmc.html - grand canonical insertions/deletions "gld"_fix_gcmc.html - generalized Langevin dynamics integrator "gravity"_fix_gravity.html - add gravity to atoms in a granular simulation "halt"_fix_halt.html - terminate a dynamics run or minimization "heat"_fix_heat.html - add/subtract momentum-conserving heat "indent"_fix_indent.html - impose force due to an indenter +"latte"_fix_latte.html - wrapper on LATTE density-functional tight-binding code "langevin"_fix_langevin.html - Langevin temperature control "lineforce"_fix_lineforce.html - constrain atoms to move in a line "momentum"_fix_momentum.html - zero the linear and/or angular momentum of a group of atoms "move"_fix_move.html - move atoms in a prescribed fashion "msst"_fix_msst.html - multi-scale shock technique (MSST) integration "neb"_fix_neb.html - nudged elastic band (NEB) spring forces "nph"_fix_nh.html - constant NPH time integration via Nose/Hoover "nphug"_fix_nphug.html - constant-stress Hugoniostat integration "nph/asphere"_fix_nph_asphere.html - NPH for aspherical particles "nph/body"_fix_nve_body.html - NPH for body particles "nph/sphere"_fix_nph_sphere.html - NPH for spherical particles "npt"_fix_nh.html - constant NPT time integration via Nose/Hoover "npt/asphere"_fix_npt_asphere.html - NPT for aspherical particles "npt/body"_fix_nve_body.html - NPT for body particles "npt/sphere"_fix_npt_sphere.html - NPT for spherical particles "nve"_fix_nve.html - constant NVE time integration "nve/asphere"_fix_nve_asphere.html - NVE for aspherical particles "nve/asphere/noforce"_fix_nve_asphere_noforce.html - NVE for aspherical particles without forces" "nve/body"_fix_nve_body.html - NVE for body particles "nve/limit"_fix_nve_limit.html - NVE with limited step length "nve/line"_fix_nve_line.html - NVE for line segments "nve/noforce"_fix_nve_noforce.html - NVE without forces (v only) "nve/sphere"_fix_nve_sphere.html - NVE for spherical particles "nve/tri"_fix_nve_tri.html - NVE for triangles "nvt"_fix_nh.html - constant NVT time integration via Nose/Hoover "nvt/asphere"_fix_nvt_asphere.html - NVT for aspherical particles "nvt/body"_fix_nve_body.html - NVT for body particles "nvt/sllod"_fix_nvt_sllod.html - NVT for NEMD with SLLOD equations "nvt/sphere"_fix_nvt_sphere.html - NVT for spherical particles "oneway"_fix_oneway.html - constrain particles on move in one direction "orient/bcc"_fix_orient.html - add grain boundary migration force for BCC "orient/fcc"_fix_orient.html - add grain boundary migration force for FCC "planeforce"_fix_planeforce.html - constrain atoms to move in a plane "poems"_fix_poems.html - constrain clusters of atoms to move \ as coupled rigid bodies "pour"_fix_pour.html - pour new atoms/molecules into a granular simulation domain "press/berendsen"_fix_press_berendsen.html - pressure control by \ Berendsen barostat "print"_fix_print.html - print text and variables during a simulation "property/atom"_fix_property_atom.html - add customized per-atom values "qeq/comb"_fix_qeq_comb.html - charge equilibration for COMB potential \ "qeq/dynamic"_fix_qeq.html - charge equilibration via dynamic method \ "qeq/fire"_fix_qeq.html - charge equilibration via FIRE minimizer \ "qeq/point"_fix_qeq.html - charge equilibration via point method \ "qeq/shielded"_fix_qeq.html - charge equilibration via shielded method \ "qeq/slater"_fix_qeq.html - charge equilibration via Slater method \ "rattle"_fix_shake.html - RATTLE constraints on bonds and/or angles "reax/bonds"_fix_reax_bonds.html - write out ReaxFF bond information \ "recenter"_fix_recenter.html - constrain the center-of-mass position \ of a group of atoms "restrain"_fix_restrain.html - constrain a bond, angle, dihedral "rigid"_fix_rigid.html - constrain one or more clusters of atoms to \ move as a rigid body with NVE integration "rigid/nph"_fix_rigid.html - constrain one or more clusters of atoms to \ move as a rigid body with NPH integration "rigid/npt"_fix_rigid.html - constrain one or more clusters of atoms to \ move as a rigid body with NPT integration "rigid/nve"_fix_rigid.html - constrain one or more clusters of atoms to \ move as a rigid body with alternate NVE integration "rigid/nvt"_fix_rigid.html - constrain one or more clusters of atoms to \ move as a rigid body with NVT integration "rigid/small"_fix_rigid.html - constrain many small clusters of atoms to \ move as a rigid body with NVE integration "rigid/small/nph"_fix_rigid.html - constrain many small clusters of atoms to \ move as a rigid body with NPH integration "rigid/small/npt"_fix_rigid.html - constrain many small clusters of atoms to \ move as a rigid body with NPT integration "rigid/small/nve"_fix_rigid.html - constrain many small clusters of atoms to \ move as a rigid body with alternate NVE integration "rigid/small/nvt"_fix_rigid.html - constrain many small clusters of atoms to \ move as a rigid body with NVT integration "setforce"_fix_setforce.html - set the force on each atom "shake"_fix_shake.html - SHAKE constraints on bonds and/or angles "spring"_fix_spring.html - apply harmonic spring force to group of atoms "spring/chunk"_fix_spring_chunk.html - apply harmonic spring force to each chunk of atoms "spring/rg"_fix_spring_rg.html - spring on radius of gyration of \ group of atoms "spring/self"_fix_spring_self.html - spring from each atom to its origin "srd"_fix_srd.html - stochastic rotation dynamics (SRD) "store/force"_fix_store_force.html - store force on each atom "store/state"_fix_store_state.html - store attributes for each atom "temp/berendsen"_fix_temp_berendsen.html - temperature control by \ Berendsen thermostat "temp/csld"_fix_temp_csvr.html - canonical sampling thermostat with Langevin dynamics "temp/csvr"_fix_temp_csvr.html - canonical sampling thermostat with Hamiltonian dynamics "temp/rescale"_fix_temp_rescale.html - temperature control by \ velocity rescaling "tfmc"_fix_tfmc.html - perform force-bias Monte Carlo with time-stamped method "thermal/conductivity"_fix_thermal_conductivity.html - Muller-Plathe kinetic energy exchange for \ thermal conductivity calculation "tmd"_fix_tmd.html - guide a group of atoms to a new configuration "ttm"_fix_ttm.html - two-temperature model for electronic/atomic coupling "tune/kspace"_fix_tune_kspace.html - auto-tune KSpace parameters "vector"_fix_vector.html - accumulate a global vector every N timesteps "viscosity"_fix_viscosity.html - Muller-Plathe momentum exchange for \ viscosity calculation "viscous"_fix_viscous.html - viscous damping for granular simulations "wall/colloid"_fix_wall.html - Lennard-Jones wall interacting with finite-size particles "wall/gran"_fix_wall_gran.html - frictional wall(s) for granular simulations "wall/harmonic"_fix_wall.html - harmonic spring wall "wall/lj1043"_fix_wall.html - Lennard-Jones 10-4-3 wall "wall/lj126"_fix_wall.html - Lennard-Jones 12-6 wall "wall/lj93"_fix_wall.html - Lennard-Jones 9-3 wall "wall/piston"_fix_wall_piston.html - moving reflective piston wall "wall/reflect"_fix_wall_reflect.html - reflecting wall(s) "wall/region"_fix_wall_region.html - use region surface as wall "wall/srd"_fix_wall_srd.html - slip/no-slip wall for SRD particles :ul [Restrictions:] Some fix styles are part of specific packages. They are only enabled if LAMMPS was built with that package. See the "Making LAMMPS"_Section_start.html#start_3 section for more info on packages. The doc pages for individual fixes tell if it is part of a package. [Related commands:] "unfix"_unfix.html, "fix_modify"_fix_modify.html [Default:] none