diff --git a/doc/Section_commands.html b/doc/Section_commands.html index e8ed4df87..225e79fab 100644 --- a/doc/Section_commands.html +++ b/doc/Section_commands.html @@ -1,473 +1,473 @@ <HTML> <CENTER><A HREF = "Section_start.html">Previous Section</A> - <A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A> - <A HREF = "Section_howto.html">Next Section</A> </CENTER> <HR> <H3>3. Commands </H3> <P>This section describes how a LAMMPS input script is formatted and what commands are used to define a LAMMPS simulation. </P> 3.1 <A HREF = "#3_1">LAMMPS input script</A><BR> 3.2 <A HREF = "#3_2">Parsing rules</A><BR> 3.3 <A HREF = "#3_3">Input script structure</A><BR> 3.4 <A HREF = "#3_4">Commands listed by category</A><BR> 3.5 <A HREF = "#3_5">Commands listed alphabetically</A> <BR> <HR> <A NAME = "3_1"></A><H4>3.1 LAMMPS input script </H4> <P>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. </P> <P>In many cases, the ordering of commands in an input script is not important. However the following rules apply: </P> <P>(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: </P> <PRE>timestep 0.5 run 100 run 100 </PRE> <P>does something different than this sequence: </P> <PRE>run 100 timestep 0.5 run 100 </PRE> <P>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. </P> <P>(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. </P> <P>(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 <A HREF = "read_data.html">read_data</A> command initializes the system by setting up the simulation box and assigning atoms to processors. If default values are not desired, the <A HREF = "processors.html">processors</A> and <A HREF = "boundary.html">boundary</A> commands need to be used before read_data to tell LAMMPS how to map processors to the simulation box. </P> <P>Many input script errors are detected by LAMMPS and an ERROR or WARNING message is printed. <A HREF = "Section_errors.html">This section</A> gives more information on what errors mean. The documentation for each command lists restrictions on how the command can be used. </P> <HR> <A NAME = "3_2"></A><H4>3.2 Parsing rules </H4> <P>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. </P> <P>Here is how each line in the input script is parsed by LAMMPS: </P> <P>(1) If the line ends with a "&" character (the "and" character which is shift-7 on most keyboards) with no trailing whitespace (and no surrounding quotes), the command is assumed to continue on the next line. The next line is concatenated to the previous line by removing the "&" character ("and" character) and newline. This allows long commands to be continued across two or more lines. </P> <P>(2) All characters from the first "#" character onward are treated as comment and discarded. </P> <P>(3) The line is searched repeatedly for $ characters which indicate variables that are replaced with a text string. 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 character immediately following the $. Thus ${myTemp} and $x refer to variable names "myTemp" and "x". See the <A HREF = "variable.html">variable</A> command for details of how strings are assigned to variables and how they are substituted for in input scripts. </P> <P>(4) The line is broken into "words" separated by whitespace (tabs, spaces). Note that words can thus contain letters, digits, underscores, or punctuation characters. </P> <P>(5) The first word is the command name. All successive words in the line are arguments. </P> <P>(6) Text with spaces can be enclosed in double quotes so it will be treated as a single argument. See the <A HREF = "dump_modify.html">dump modify</A> or <A HREF = "fix_print.html">fix print</A> commands for examples. A '#' or '$' character that is in text between double quotes will not be treated as a comment or substituted for as a variable. </P> <HR> <H4><A NAME = "3_3"></A>3.3 Input script structure </H4> <P>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 <A HREF = "Section_example.html">this section</A>, and animated on the <A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A>. </P> <P>A LAMMPS input script typically has 4 parts: </P> <OL><LI>Initialization <LI>Atom definition <LI>Settings <LI>Run a simulation </OL> <P>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. </P> <P>(1) Initialization </P> <P>Set parameters that need to be defined before atoms are created or read-in from a file. </P> <P>The relevant commands are <A HREF = "units.html">units</A>, <A HREF = "dimension.html">dimension</A>, <A HREF = "newton.html">newton</A>, <A HREF = "processors.html">processors</A>, <A HREF = "boundary.html">boundary</A>, <A HREF = "atom_style.html">atom_style</A>, <A HREF = "atom_modify.html">atom_modify</A>. </P> <P>If force-field parameters appear in the files that will be read, these commands tell LAMMPS what kinds of force fields are being used: <A HREF = "pair_style.html">pair_style</A>, <A HREF = "bond_style.html">bond_style</A>, <A HREF = "angle_style.html">angle_style</A>, <A HREF = "dihedral_style.html">dihedral_style</A>, <A HREF = "improper_style.html">improper_style</A>. </P> <P>(2) Atom definition </P> <P>There are 3 ways to define atoms in LAMMPS. Read them in from a data or restart file via the <A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A> commands. These files can contain molecular topology information. Or create atoms on a lattice (with no molecular topology), using these commands: <A HREF = "lattice.html">lattice</A>, <A HREF = "region.html">region</A>, <A HREF = "create_box.html">create_box</A>, <A HREF = "create_atoms.html">create_atoms</A>. The entire set of atoms can be duplicated to make a larger simulation using the <A HREF = "replicate.html">replicate</A> command. </P> <P>(3) Settings </P> <P>Once atoms and molecular topology are defined, a variety of settings can be specified: force field coefficients, simulation parameters, output options, etc. </P> <P>Force field coefficients are set by these commands (they can also be set in the read-in files): <A HREF = "pair_coeff.html">pair_coeff</A>, <A HREF = "bond_coeff.html">bond_coeff</A>, <A HREF = "angle_coeff.html">angle_coeff</A>, <A HREF = "dihedral_coeff.html">dihedral_coeff</A>, <A HREF = "improper_coeff.html">improper_coeff</A>, <A HREF = "kspace_style.html">kspace_style</A>, <A HREF = "dielectric.html">dielectric</A>, <A HREF = "special_bonds.html">special_bonds</A>. </P> <P>Various simulation parameters are set by these commands: <A HREF = "neighbor.html">neighbor</A>, <A HREF = "neigh_modify.html">neigh_modify</A>, <A HREF = "group.html">group</A>, <A HREF = "timestep.html">timestep</A>, <A HREF = "reset_timestep.html">reset_timestep</A>, <A HREF = "run_style.html">run_style</A>, <A HREF = "min_style.html">min_style</A>, <A HREF = "min_modify.html">min_modify</A>. </P> <P>Fixes impose a variety of boundary conditions, time integration, and diagnostic options. The <A HREF = "fix.html">fix</A> command comes in many flavors. </P> <P>Various computations can be specified for execution during a simulation using the <A HREF = "compute.html">compute</A>, <A HREF = "compute_modify.html">compute_modify</A>, and <A HREF = "variable.html">variable</A> commands. </P> <P>Output options are set by the <A HREF = "thermo.html">thermo</A>, <A HREF = "dump.html">dump</A>, and <A HREF = "restart.html">restart</A> commands. </P> <P>(4) Run a simulation </P> <P>A molecular dynamics simulation is run using the <A HREF = "run.html">run</A> command. Energy minimization (molecular statics) is performed using the <A HREF = "minimize.html">minimize</A> command. A parallel tempering (replica-exchange) simulation can be run using the <A HREF = "temper.html">temper</A> command. </P> <HR> <A NAME = "3_4"></A><H4>3.4 Commands listed by category </H4> <P>This section lists all LAMMPS commands, grouped by category. The <A HREF = "#3_5">next section</A> lists the same commands alphabetically. 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. </P> <P>Initialization: </P> <P><A HREF = "atom_modify.html">atom_modify</A>, <A HREF = "atom_style.html">atom_style</A>, <A HREF = "boundary.html">boundary</A>, <A HREF = "dimension.html">dimension</A>, <A HREF = "newton.html">newton</A>, <A HREF = "processors.html">processors</A>, <A HREF = "units.html">units</A> </P> <P>Atom definition: </P> <P><A HREF = "create_atoms.html">create_atoms</A>, <A HREF = "create_box.html">create_box</A>, <A HREF = "lattice.html">lattice</A>, <A HREF = "read_data.html">read_data</A>, <A HREF = "read_restart.html">read_restart</A>, <A HREF = "region.html">region</A>, <A HREF = "replicate.html">replicate</A> </P> <P>Force fields: </P> <P><A HREF = "angle_coeff.html">angle_coeff</A>, <A HREF = "angle_style.html">angle_style</A>, <A HREF = "bond_coeff.html">bond_coeff</A>, <A HREF = "bond_style.html">bond_style</A>, <A HREF = "dielectric.html">dielectric</A>, <A HREF = "dihedral_coeff.html">dihedral_coeff</A>, <A HREF = "dihedral_style.html">dihedral_style</A>, <A HREF = "improper_coeff.html">improper_coeff</A>, <A HREF = "improper_style.html">improper_style</A>, <A HREF = "kspace_modify.html">kspace_modify</A>, <A HREF = "kspace_style.html">kspace_style</A>, <A HREF = "pair_coeff.html">pair_coeff</A>, <A HREF = "pair_modify.html">pair_modify</A>, <A HREF = "pair_style.html">pair_style</A>, <A HREF = "pair_write.html">pair_write</A>, <A HREF = "special_bonds.html">special_bonds</A> </P> <P>Settings: </P> <P><A HREF = "communicate.html">communicate</A>, <A HREF = "dipole.html">dipole</A>, <A HREF = "group.html">group</A>, <A HREF = "mass.html">mass</A>, <A HREF = "min_modify.html">min_modify</A>, <A HREF = "min_style.html">min_style</A>, <A HREF = "neigh_modify.html">neigh_modify</A>, <A HREF = "neighbor.html">neighbor</A>, <A HREF = "reset_timestep.html">reset_timestep</A>, <A HREF = "run_style.html">run_style</A>, <A HREF = "set.html">set</A>, <A HREF = "shape.html">shape</A>, <A HREF = "timestep.html">timestep</A>, <A HREF = "velocity.html">velocity</A> </P> <P>Fixes: </P> <P><A HREF = "fix.html">fix</A>, <A HREF = "fix_modify.html">fix_modify</A>, <A HREF = "unfix.html">unfix</A> </P> <P>Computes: </P> <P><A HREF = "compute.html">compute</A>, <A HREF = "compute_modify.html">compute_modify</A>, <A HREF = "uncompute.html">uncompute</A> </P> <P>Output: </P> <P><A HREF = "dump.html">dump</A>, <A HREF = "dump_modify.html">dump_modify</A>, <A HREF = "restart.html">restart</A>, <A HREF = "thermo.html">thermo</A>, <A HREF = "thermo_modify.html">thermo_modify</A>, <A HREF = "thermo_style.html">thermo_style</A>, <A HREF = "undump.html">undump</A>, <A HREF = "write_restart.html">write_restart</A> </P> <P>Actions: </P> <P><A HREF = "delete_atoms.html">delete_atoms</A>, <A HREF = "delete_bonds.html">delete_bonds</A>, <A HREF = "displace_atoms.html">displace_atoms</A>, <A HREF = "displace_box.html">displace_box</A>, <A HREF = "minimize.html">minimize</A>, <A HREF = "prd.html">prd</A>, <A HREF = "run.html">run</A>, <A HREF = "temper.html">temper</A> </P> <P>Miscellaneous: </P> <P><A HREF = "clear.html">clear</A>, <A HREF = "echo.html">echo</A>, <A HREF = "if.html">if</A>, <A HREF = "include.html">include</A>, <A HREF = "jump.html">jump</A>, <A HREF = "label.html">label</A>, <A HREF = "log.html">log</A>, <A HREF = "next.html">next</A>, <A HREF = "print.html">print</A>, <A HREF = "shell.html">shell</A>, <A HREF = "variable.html">variable</A> </P> <HR> <H4><A NAME = "3_5"></A><A NAME = "comm"></A>3.5 Individual commands </H4> <P>This section lists all LAMMPS commands alphabetically, with a separate listing below of styles within certain commands. The <A HREF = "#3_4">previous section</A> 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. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "angle_coeff.html">angle_coeff</A></TD><TD ><A HREF = "angle_style.html">angle_style</A></TD><TD ><A HREF = "atom_modify.html">atom_modify</A></TD><TD ><A HREF = "atom_style.html">atom_style</A></TD><TD ><A HREF = "bond_coeff.html">bond_coeff</A></TD><TD ><A HREF = "bond_style.html">bond_style</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "boundary.html">boundary</A></TD><TD ><A HREF = "change_box.html">change_box</A></TD><TD ><A HREF = "clear.html">clear</A></TD><TD ><A HREF = "communicate.html">communicate</A></TD><TD ><A HREF = "compute.html">compute</A></TD><TD ><A HREF = "compute_modify.html">compute_modify</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "create_atoms.html">create_atoms</A></TD><TD ><A HREF = "create_box.html">create_box</A></TD><TD ><A HREF = "delete_atoms.html">delete_atoms</A></TD><TD ><A HREF = "delete_bonds.html">delete_bonds</A></TD><TD ><A HREF = "dielectric.html">dielectric</A></TD><TD ><A HREF = "dihedral_coeff.html">dihedral_coeff</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "dihedral_style.html">dihedral_style</A></TD><TD ><A HREF = "dimension.html">dimension</A></TD><TD ><A HREF = "dipole.html">dipole</A></TD><TD ><A HREF = "displace_atoms.html">displace_atoms</A></TD><TD ><A HREF = "displace_box.html">displace_box</A></TD><TD ><A HREF = "dump.html">dump</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "dump_modify.html">dump_modify</A></TD><TD ><A HREF = "echo.html">echo</A></TD><TD ><A HREF = "fix.html">fix</A></TD><TD ><A HREF = "fix_modify.html">fix_modify</A></TD><TD ><A HREF = "group.html">group</A></TD><TD ><A HREF = "if.html">if</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "improper_coeff.html">improper_coeff</A></TD><TD ><A HREF = "improper_style.html">improper_style</A></TD><TD ><A HREF = "include.html">include</A></TD><TD ><A HREF = "jump.html">jump</A></TD><TD ><A HREF = "kspace_modify.html">kspace_modify</A></TD><TD ><A HREF = "kspace_style.html">kspace_style</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "label.html">label</A></TD><TD ><A HREF = "lattice.html">lattice</A></TD><TD ><A HREF = "log.html">log</A></TD><TD ><A HREF = "mass.html">mass</A></TD><TD ><A HREF = "minimize.html">minimize</A></TD><TD ><A HREF = "min_modify.html">min_modify</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "min_style.html">min_style</A></TD><TD ><A HREF = "neigh_modify.html">neigh_modify</A></TD><TD ><A HREF = "neighbor.html">neighbor</A></TD><TD ><A HREF = "newton.html">newton</A></TD><TD ><A HREF = "next.html">next</A></TD><TD ><A HREF = "pair_coeff.html">pair_coeff</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_modify.html">pair_modify</A></TD><TD ><A HREF = "pair_style.html">pair_style</A></TD><TD ><A HREF = "pair_write.html">pair_write</A></TD><TD ><A HREF = "prd.html">prd</A></TD><TD ><A HREF = "print.html">print</A></TD><TD ><A HREF = "processors.html">processors</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "read_data.html">read_data</A></TD><TD ><A HREF = "read_restart.html">read_restart</A></TD><TD ><A HREF = "region.html">region</A></TD><TD ><A HREF = "replicate.html">replicate</A></TD><TD ><A HREF = "reset_timestep.html">reset_timestep</A></TD><TD ><A HREF = "restart.html">restart</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "run.html">run</A></TD><TD ><A HREF = "run_style.html">run_style</A></TD><TD ><A HREF = "set.html">set</A></TD><TD ><A HREF = "shape.html">shape</A></TD><TD ><A HREF = "shell.html">shell</A></TD><TD ><A HREF = "special_bonds.html">special_bonds</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "temper.html">temper</A></TD><TD ><A HREF = "thermo.html">thermo</A></TD><TD ><A HREF = "thermo_modify.html">thermo_modify</A></TD><TD ><A HREF = "thermo_style.html">thermo_style</A></TD><TD ><A HREF = "timestep.html">timestep</A></TD><TD ><A HREF = "uncompute.html">uncompute</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "undump.html">undump</A></TD><TD ><A HREF = "unfix.html">unfix</A></TD><TD ><A HREF = "units.html">units</A></TD><TD ><A HREF = "variable.html">variable</A></TD><TD ><A HREF = "velocity.html">velocity</A></TD><TD ><A HREF = "write_restart.html">write_restart</A> </TD></TR></TABLE></DIV> <HR> <H4>Fix styles </H4> <P>See the <A HREF = "fix.html">fix</A> command for one-line descriptions of each style or click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "fix_addforce.html">addforce</A></TD><TD ><A HREF = "fix_aveforce.html">aveforce</A></TD><TD ><A HREF = "fix_ave_atom.html">ave/atom</A></TD><TD ><A HREF = "fix_ave_spatial.html">ave/spatial</A></TD><TD ><A HREF = "fix_ave_time.html">ave/time</A></TD><TD ><A HREF = "fix_bond_break.html">bond/break</A></TD><TD ><A HREF = "fix_bond_create.html">bond/create</A></TD><TD ><A HREF = "fix_bond_swap.html">bond/swap</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_box_relax.html">box/relax</A></TD><TD ><A HREF = "fix_com.html">com</A></TD><TD ><A HREF = "fix_coord_original.html">coord/original</A></TD><TD ><A HREF = "fix_deform.html">deform</A></TD><TD ><A HREF = "fix_deposit.html">deposit</A></TD><TD ><A HREF = "fix_drag.html">drag</A></TD><TD ><A HREF = "fix_dt_reset.html">dt/reset</A></TD><TD ><A HREF = "fix_efield.html">efield</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_enforce2d.html">enforce2d</A></TD><TD ><A HREF = "fix_evaporate.html">evaporate</A></TD><TD ><A HREF = "fix_freeze.html">freeze</A></TD><TD ><A HREF = "fix_gravity.html">gravity</A></TD><TD ><A HREF = "fix_gyration.html">gyration</A></TD><TD ><A HREF = "fix_heat.html">heat</A></TD><TD ><A HREF = "fix_indent.html">indent</A></TD><TD ><A HREF = "fix_langevin.html">langevin</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_lineforce.html">lineforce</A></TD><TD ><A HREF = "fix_msd.html">msd</A></TD><TD ><A HREF = "fix_momentum.html">momentum</A></TD><TD ><A HREF = "fix_move.html">move</A></TD><TD ><A HREF = "fix_nph.html">nph</A></TD><TD ><A HREF = "fix_npt.html">npt</A></TD><TD ><A HREF = "fix_npt_asphere.html">npt/asphere</A></TD><TD ><A HREF = "fix_npt_sphere.html">npt/sphere</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_nve.html">nve</A></TD><TD ><A HREF = "fix_nve_asphere.html">nve/asphere</A></TD><TD ><A HREF = "fix_nve_limit.html">nve/limit</A></TD><TD ><A HREF = "fix_nve_noforce.html">nve/noforce</A></TD><TD ><A HREF = "fix_nve_sphere.html">nve/sphere</A></TD><TD ><A HREF = "fix_nvt.html">nvt</A></TD><TD ><A HREF = "fix_nvt_asphere.html">nvt/asphere</A></TD><TD ><A HREF = "fix_nvt_sllod.html">nvt/sllod</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_nvt_sphere.html">nvt/sphere</A></TD><TD ><A HREF = "fix_orient_fcc.html">orient/fcc</A></TD><TD ><A HREF = "fix_planeforce.html">planeforce</A></TD><TD ><A HREF = "fix_poems.html">poems</A></TD><TD ><A HREF = "fix_pour.html">pour</A></TD><TD ><A HREF = "fix_press_berendsen.html">press/berendsen</A></TD><TD ><A HREF = "fix_print.html">print</A></TD><TD ><A HREF = "fix_rdf.html">rdf</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_reax_bonds.html">reax/bonds</A></TD><TD ><A HREF = "fix_recenter.html">recenter</A></TD><TD ><A HREF = "fix_rigid.html">rigid</A></TD><TD ><A HREF = "fix_setforce.html">setforce</A></TD><TD ><A HREF = "fix_shake.html">shake</A></TD><TD ><A HREF = "fix_spring.html">spring</A></TD><TD ><A HREF = "fix_spring_rg.html">spring/rg</A></TD><TD ><A HREF = "fix_spring_self.html">spring/self</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_temp_berendsen.html">temp/berendsen</A></TD><TD ><A HREF = "fix_temp_rescale.html">temp/rescale</A></TD><TD ><A HREF = "fix_thermal_conductivity.html">thermal/conductivity</A></TD><TD ><A HREF = "fix_tmd.html">tmd</A></TD><TD ><A HREF = "fix_ttm.html">ttm</A></TD><TD ><A HREF = "fix_viscosity.html">viscosity</A></TD><TD ><A HREF = "fix_viscous.html">viscous</A></TD><TD ><A HREF = "fix_wall.html">wall/colloid</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "fix_wall_gran.html">wall/gran</A></TD><TD ><A HREF = "fix_wall.html">wall/lj126</A></TD><TD ><A HREF = "fix_wall.html">wall/lj93</A></TD><TD ><A HREF = "fix_wall_reflect.html">wall/reflect</A> </TD></TR></TABLE></DIV> <P>These are fix styles contributed by users, which can be used if <A HREF = "Section_start.html#2_3">LAMMPS is built with the appropriate package</A>. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "fix_atc.html">atc</A></TD><TD ><A HREF = "fix_imd.html">imd</A></TD><TD ><A HREF = "fix_smd.html">smd</A> </TD></TR></TABLE></DIV> <HR> <H4>Compute styles </H4> <P>See the <A HREF = "compute.html">compute</A> command for one-line descriptions of each style or click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "compute_centro_atom.html">centro/atom</A></TD><TD ><A HREF = "compute_cna_atom.html">cna/atom</A></TD><TD ><A HREF = "compute_com.html">com</A></TD><TD ><A HREF = "compute_coord_atom.html">coord/atom</A></TD><TD ><A HREF = "compute_damage_atom.html">damage/atom</A></TD><TD ><A HREF = "compute_displace_atom.html">displace/atom</A></TD></TR> -<TR ALIGN="center"><TD ><A HREF = "compute_erotate_asphere.html">erotate/asphere</A></TD><TD ><A HREF = "compute_erotate_sphere.html">erotate/sphere</A></TD><TD ><A HREF = "compute_event_displace.html">event/displace</A></TD><TD ><A HREF = "compute_group_group.html">group/group</A></TD><TD ><A HREF = "compute_heat_flux.html">heat/flux</A></TD><TD ><A HREF = "compute_ke.html">ke</A></TD></TR> -<TR ALIGN="center"><TD ><A HREF = "compute_ke_atom.html">ke/atom</A></TD><TD ><A HREF = "compute_msd.html">msd</A></TD><TD ><A HREF = "compute_pe.html">pe</A></TD><TD ><A HREF = "compute_pe_atom.html">pe/atom</A></TD><TD ><A HREF = "compute_pressure.html">pressure</A></TD><TD ><A HREF = "compute_reduce.html">reduce</A></TD></TR> -<TR ALIGN="center"><TD ><A HREF = "compute_reduce.html">reduce/region</A></TD><TD ><A HREF = "compute_stress_atom.html">stress/atom</A></TD><TD ><A HREF = "compute_temp.html">temp</A></TD><TD ><A HREF = "compute_temp_asphere.html">temp/asphere</A></TD><TD ><A HREF = "compute_temp_com.html">temp/com</A></TD><TD ><A HREF = "compute_temp_deform.html">temp/deform</A></TD></TR> -<TR ALIGN="center"><TD ><A HREF = "compute_temp_partial.html">temp/partial</A></TD><TD ><A HREF = "compute_temp_profile.html">temp/profile</A></TD><TD ><A HREF = "compute_temp_ramp.html">temp/ramp</A></TD><TD ><A HREF = "compute_temp_region.html">temp/region</A></TD><TD ><A HREF = "compute_temp_sphere.html">temp/sphere</A> +<TR ALIGN="center"><TD ><A HREF = "compute_erotate_asphere.html">erotate/asphere</A></TD><TD ><A HREF = "compute_erotate_sphere.html">erotate/sphere</A></TD><TD ><A HREF = "compute_event_displace.html">event/displace</A></TD><TD ><A HREF = "compute_group_group.html">group/group</A></TD><TD ><A HREF = "compute_gyration.html">gyration</A></TD><TD ><A HREF = "compute_heat_flux.html">heat/flux</A></TD></TR> +<TR ALIGN="center"><TD ><A HREF = "compute_ke.html">ke</A></TD><TD ><A HREF = "compute_ke_atom.html">ke/atom</A></TD><TD ><A HREF = "compute_msd.html">msd</A></TD><TD ><A HREF = "compute_pe.html">pe</A></TD><TD ><A HREF = "compute_pe_atom.html">pe/atom</A></TD><TD ><A HREF = "compute_pressure.html">pressure</A></TD></TR> +<TR ALIGN="center"><TD ><A HREF = "compute_reduce.html">reduce</A></TD><TD ><A HREF = "compute_reduce.html">reduce/region</A></TD><TD ><A HREF = "compute_stress_atom.html">stress/atom</A></TD><TD ><A HREF = "compute_temp.html">temp</A></TD><TD ><A HREF = "compute_temp_asphere.html">temp/asphere</A></TD><TD ><A HREF = "compute_temp_com.html">temp/com</A></TD></TR> +<TR ALIGN="center"><TD ><A HREF = "compute_temp_deform.html">temp/deform</A></TD><TD ><A HREF = "compute_temp_partial.html">temp/partial</A></TD><TD ><A HREF = "compute_temp_profile.html">temp/profile</A></TD><TD ><A HREF = "compute_temp_ramp.html">temp/ramp</A></TD><TD ><A HREF = "compute_temp_region.html">temp/region</A></TD><TD ><A HREF = "compute_temp_sphere.html">temp/sphere</A> </TD></TR></TABLE></DIV> <P>These are compute styles contributed by users, which can be used if <A HREF = "Section_start.html#2_3">LAMMPS is built with the appropriate package</A>. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "compute_ackland_atom.html">ackland/atom</A> </TD></TR></TABLE></DIV> <HR> <H4>Pair_style potentials </H4> <P>See the <A HREF = "pair_style.html">pair_style</A> command for an overview of pair potentials. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "pair_none.html">none</A></TD><TD ><A HREF = "pair_hybrid.html">hybrid</A></TD><TD ><A HREF = "pair_hybrid.html">hybrid/overlay</A></TD><TD ><A HREF = "pair_airebo.html">airebo</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_born.html">born/coul/long</A></TD><TD ><A HREF = "pair_buck.html">buck</A></TD><TD ><A HREF = "pair_buck.html">buck/coul/cut</A></TD><TD ><A HREF = "pair_buck.html">buck/coul/long</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_colloid.html">colloid</A></TD><TD ><A HREF = "pair_coul.html">coul/cut</A></TD><TD ><A HREF = "pair_coul.html">coul/debye</A></TD><TD ><A HREF = "pair_coul.html">coul/long</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_dipole.html">dipole/cut</A></TD><TD ><A HREF = "pair_dpd.html">dpd</A></TD><TD ><A HREF = "pair_dsmc.html">dsmc</A></TD><TD ><A HREF = "pair_eam.html">eam</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam/opt</A></TD><TD ><A HREF = "pair_eam.html">eam/alloy</A></TD><TD ><A HREF = "pair_eam.html">eam/alloy/opt</A></TD><TD ><A HREF = "pair_eam.html">eam/fs</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam/fs/opt</A></TD><TD ><A HREF = "pair_gayberne.html">gayberne</A></TD><TD ><A HREF = "pair_gayberne.html">gayberne/gpu</A></TD><TD ><A HREF = "pair_gran.html">gran/hertz/history</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_gran.html">gran/hooke</A></TD><TD ><A HREF = "pair_gran.html">gran/hooke/history</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm/implicit</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long/opt</A></TD><TD ><A HREF = "pair_class2.html">lj/class2</A></TD><TD ><A HREF = "pair_class2.html">lj/class2/coul/cut</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_class2.html">lj/class2/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/gpu</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/opt</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_lj.html">lj/cut/coul/cut</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/debye</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long/tip4p</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_lj_expand.html">lj/expand</A></TD><TD ><A HREF = "pair_gromacs.html">lj/gromacs</A></TD><TD ><A HREF = "pair_gromacs.html">lj/gromacs/coul/gromacs</A></TD><TD ><A HREF = "pair_lj_smooth.html">lj/smooth</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_lj96_cut.html">lj96/cut</A></TD><TD ><A HREF = "pair_lubricate.html">lubricate</A></TD><TD ><A HREF = "pair_meam.html">meam</A></TD><TD ><A HREF = "pair_morse.html">morse</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_morse.html">morse/opt</A></TD><TD ><A HREF = "pair_peri_pmb.html">peri/pmb</A></TD><TD ><A HREF = "pair_reax.html">reax</A></TD><TD ><A HREF = "pair_resquared.html">resquared</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_soft.html">soft</A></TD><TD ><A HREF = "pair_sw.html">sw</A></TD><TD ><A HREF = "pair_table.html">table</A></TD><TD ><A HREF = "pair_tersoff.html">tersoff</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_tersoff_zbl.html">tersoff/zbl</A></TD><TD ><A HREF = "pair_yukawa.html">yukawa</A></TD><TD ><A HREF = "pair_yukawa_colloid.html">yukawa/colloid</A> </TD></TR></TABLE></DIV> <P>These are pair styles contributed by users, which can be used if <A HREF = "Section_start.html#2_3">LAMMPS is built with the appropriate package</A>. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "pair_buck_coul.html">buck/coul</A></TD><TD ><A HREF = "pair_cmm.html">cg/cmm</A></TD><TD ><A HREF = "pair_cmm.html">cg/cmm/coul/cut</A></TD><TD ><A HREF = "pair_cmm.html">cg/cmm/coul/long</A></TD></TR> <TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam/cd</A></TD><TD ><A HREF = "pair_lj_coul.html">lj/coul</A> </TD></TR></TABLE></DIV> <HR> <H4>Bond_style potentials </H4> <P>See the <A HREF = "bond_style.html">bond_style</A> command for an overview of bond potentials. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "bond_none.html">none</A></TD><TD WIDTH="100"><A HREF = "bond_hybrid.html">hybrid</A></TD><TD WIDTH="100"><A HREF = "bond_class2.html">class2</A></TD><TD WIDTH="100"><A HREF = "bond_fene.html">fene</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "bond_fene_expand.html">fene/expand</A></TD><TD WIDTH="100"><A HREF = "bond_harmonic.html">harmonic</A></TD><TD WIDTH="100"><A HREF = "bond_morse.html">morse</A></TD><TD WIDTH="100"><A HREF = "bond_nonlinear.html">nonlinear</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "bond_quartic.html">quartic</A></TD><TD WIDTH="100"><A HREF = "bond_table.html">table</A> </TD></TR></TABLE></DIV> <HR> <H4>Angle_style potentials </H4> <P>See the <A HREF = "angle_style.html">angle_style</A> command for an overview of angle potentials. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "angle_none.html">none</A></TD><TD WIDTH="100"><A HREF = "angle_hybrid.html">hybrid</A></TD><TD WIDTH="100"><A HREF = "angle_charmm.html">charmm</A></TD><TD WIDTH="100"><A HREF = "angle_class2.html">class2</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "angle_cosine.html">cosine</A></TD><TD WIDTH="100"><A HREF = "angle_cosine_delta.html">cosine/delta</A></TD><TD WIDTH="100"><A HREF = "angle_cosine_squared.html">cosine/squared</A></TD><TD WIDTH="100"><A HREF = "angle_harmonic.html">harmonic</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "angle_table.html">table</A> </TD></TR></TABLE></DIV> <P>These are angle styles contributed by users, which can be used if <A HREF = "Section_start.html#2_3">LAMMPS is built with the appropriate package</A>. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD ><A HREF = "angle_cmm.html">cg/cmm</A> </TD></TR></TABLE></DIV> <HR> <H4>Dihedral_style potentials </H4> <P>See the <A HREF = "dihedral_style.html">dihedral_style</A> command for an overview of dihedral potentials. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "dihedral_none.html">none</A></TD><TD WIDTH="100"><A HREF = "dihedral_hybrid.html">hybrid</A></TD><TD WIDTH="100"><A HREF = "dihedral_charmm.html">charmm</A></TD><TD WIDTH="100"><A HREF = "dihedral_class2.html">class2</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "dihedral_harmonic.html">harmonic</A></TD><TD WIDTH="100"><A HREF = "dihedral_helix.html">helix</A></TD><TD WIDTH="100"><A HREF = "dihedral_multi_harmonic.html">multi/harmonic</A></TD><TD WIDTH="100"><A HREF = "dihedral_opls.html">opls</A> </TD></TR></TABLE></DIV> <HR> <H4>Improper_style potentials </H4> <P>See the <A HREF = "improper_style.html">improper_style</A> command for an overview of improper potentials. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "improper_none.html">none</A></TD><TD WIDTH="100"><A HREF = "improper_hybrid.html">hybrid</A></TD><TD WIDTH="100"><A HREF = "improper_class2.html">class2</A></TD><TD WIDTH="100"><A HREF = "improper_cvff.html">cvff</A></TD></TR> <TR ALIGN="center"><TD WIDTH="100"><A HREF = "improper_harmonic.html">harmonic</A> </TD></TR></TABLE></DIV> <HR> <H4>Kspace solvers </H4> <P>See the <A HREF = "kspace_style.html">kspace_style</A> command for an overview of Kspace solvers. Click on the style itself for a full description: </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "kspace_style.html">ewald</A></TD><TD WIDTH="100"><A HREF = "kspace_style.html">pppm</A></TD><TD WIDTH="100"><A HREF = "kspace_style.html">pppm/tip4p</A> </TD></TR></TABLE></DIV> <P>These are Kspace solvers contributed by users, which can be used if <A HREF = "Section_start.html#2_3">LAMMPS is built with the appropriate package</A>. </P> <DIV ALIGN=center><TABLE BORDER=1 > <TR ALIGN="center"><TD WIDTH="100"><A HREF = "kspace_style.html">ewald/n</A> </TD></TR></TABLE></DIV> </HTML> diff --git a/doc/Section_commands.txt b/doc/Section_commands.txt index 06f29cbd6..b340b1dad 100644 --- a/doc/Section_commands.txt +++ b/doc/Section_commands.txt @@ -1,662 +1,663 @@ "Previous Section"_Section_start.html - "LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc - "Next Section"_Section_howto.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 what commands are used to define a LAMMPS simulation. 3.1 "LAMMPS input script"_#3_1 3.2 "Parsing rules"_#3_2 3.3 "Input script structure"_#3_3 3.4 "Commands listed by category"_#3_4 3.5 "Commands listed alphabetically"_#3_5 :all(b) :line 3.1 LAMMPS input script :link(3_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(3_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 line ends with a "&" character (the "and" character which is shift-7 on most keyboards) with no trailing whitespace (and no surrounding quotes), the command is assumed to continue on the next line. The next line is concatenated to the previous line by removing the "&" character ("and" character) and newline. This allows long commands to be continued across two or more lines. (2) All characters from the first "#" character onward are treated as comment and discarded. (3) The line is searched repeatedly for $ characters which indicate variables that are replaced with a text string. 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 character immediately following the $. Thus $\{myTemp\} and $x refer to variable names "myTemp" and "x". See the "variable"_variable.html command for details of how strings are assigned to variables and how they are substituted for in input scripts. (4) The line is broken into "words" separated by whitespace (tabs, spaces). Note that words can thus contain letters, digits, underscores, or punctuation characters. (5) The first word is the command name. All successive words in the line are arguments. (6) Text with spaces can be enclosed in double quotes so it will be treated as a single argument. See the "dump modify"_dump_modify.html or "fix print"_fix_print.html commands for examples. A '#' or '$' character that is in text between double quotes will not be treated as a comment or substituted for as a variable. :line 3.3 Input script structure :h4,link(3_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 "this section"_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(3_4),h4 This section lists all LAMMPS commands, grouped by category. The "next section"_#3_5 lists the same commands alphabetically. 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. Initialization: "atom_modify"_atom_modify.html, "atom_style"_atom_style.html, "boundary"_boundary.html, "dimension"_dimension.html, "newton"_newton.html, "processors"_processors.html, "units"_units.html Atom definition: "create_atoms"_create_atoms.html, "create_box"_create_box.html, "lattice"_lattice.html, "read_data"_read_data.html, "read_restart"_read_restart.html, "region"_region.html, "replicate"_replicate.html Force fields: "angle_coeff"_angle_coeff.html, "angle_style"_angle_style.html, "bond_coeff"_bond_coeff.html, "bond_style"_bond_style.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: "communicate"_communicate.html, "dipole"_dipole.html, "group"_group.html, "mass"_mass.html, "min_modify"_min_modify.html, "min_style"_min_style.html, "neigh_modify"_neigh_modify.html, "neighbor"_neighbor.html, "reset_timestep"_reset_timestep.html, "run_style"_run_style.html, "set"_set.html, "shape"_shape.html, "timestep"_timestep.html, "velocity"_velocity.html Fixes: "fix"_fix.html, "fix_modify"_fix_modify.html, "unfix"_unfix.html Computes: "compute"_compute.html, "compute_modify"_compute_modify.html, "uncompute"_uncompute.html Output: "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_restart"_write_restart.html Actions: "delete_atoms"_delete_atoms.html, "delete_bonds"_delete_bonds.html, "displace_atoms"_displace_atoms.html, "displace_box"_displace_box.html, "minimize"_minimize.html, "prd"_prd.html, "run"_run.html, "temper"_temper.html Miscellaneous: "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, "shell"_shell.html, "variable"_variable.html :line 3.5 Individual commands :h4,link(3_5),link(comm) This section lists all LAMMPS commands alphabetically, with a separate listing below of styles within certain commands. The "previous section"_#3_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, "bond_coeff"_bond_coeff.html, "bond_style"_bond_style.html, "boundary"_boundary.html, "change_box"_change_box.html, "clear"_clear.html, "communicate"_communicate.html, "compute"_compute.html, "compute_modify"_compute_modify.html, "create_atoms"_create_atoms.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, "dipole"_dipole.html, "displace_atoms"_displace_atoms.html, "displace_box"_displace_box.html, "dump"_dump.html, "dump_modify"_dump_modify.html, "echo"_echo.html, "fix"_fix.html, "fix_modify"_fix_modify.html, "group"_group.html, "if"_if.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, "neigh_modify"_neigh_modify.html, "neighbor"_neighbor.html, "newton"_newton.html, "next"_next.html, "pair_coeff"_pair_coeff.html, "pair_modify"_pair_modify.html, "pair_style"_pair_style.html, "pair_write"_pair_write.html, "prd"_prd.html, "print"_print.html, "processors"_processors.html, "read_data"_read_data.html, "read_restart"_read_restart.html, "region"_region.html, "replicate"_replicate.html, "reset_timestep"_reset_timestep.html, "restart"_restart.html, "run"_run.html, "run_style"_run_style.html, "set"_set.html, "shape"_shape.html, "shell"_shell.html, "special_bonds"_special_bonds.html, "temper"_temper.html, "thermo"_thermo.html, "thermo_modify"_thermo_modify.html, "thermo_style"_thermo_style.html, "timestep"_timestep.html, "uncompute"_uncompute.html, "undump"_undump.html, "unfix"_unfix.html, "units"_units.html, "variable"_variable.html, "velocity"_velocity.html, "write_restart"_write_restart.html :tb(c=6,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: "addforce"_fix_addforce.html, "aveforce"_fix_aveforce.html, "ave/atom"_fix_ave_atom.html, "ave/spatial"_fix_ave_spatial.html, "ave/time"_fix_ave_time.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, "com"_fix_com.html, "coord/original"_fix_coord_original.html, "deform"_fix_deform.html, "deposit"_fix_deposit.html, "drag"_fix_drag.html, "dt/reset"_fix_dt_reset.html, "efield"_fix_efield.html, "enforce2d"_fix_enforce2d.html, "evaporate"_fix_evaporate.html, "freeze"_fix_freeze.html, "gravity"_fix_gravity.html, "gyration"_fix_gyration.html, "heat"_fix_heat.html, "indent"_fix_indent.html, "langevin"_fix_langevin.html, "lineforce"_fix_lineforce.html, "msd"_fix_msd.html, "momentum"_fix_momentum.html, "move"_fix_move.html, "nph"_fix_nph.html, "npt"_fix_npt.html, "npt/asphere"_fix_npt_asphere.html, "npt/sphere"_fix_npt_sphere.html, "nve"_fix_nve.html, "nve/asphere"_fix_nve_asphere.html, "nve/limit"_fix_nve_limit.html, "nve/noforce"_fix_nve_noforce.html, "nve/sphere"_fix_nve_sphere.html, "nvt"_fix_nvt.html, "nvt/asphere"_fix_nvt_asphere.html, "nvt/sllod"_fix_nvt_sllod.html, "nvt/sphere"_fix_nvt_sphere.html, "orient/fcc"_fix_orient_fcc.html, "planeforce"_fix_planeforce.html, "poems"_fix_poems.html, "pour"_fix_pour.html, "press/berendsen"_fix_press_berendsen.html, "print"_fix_print.html, "rdf"_fix_rdf.html, "reax/bonds"_fix_reax_bonds.html, "recenter"_fix_recenter.html, "rigid"_fix_rigid.html, "setforce"_fix_setforce.html, "shake"_fix_shake.html, "spring"_fix_spring.html, "spring/rg"_fix_spring_rg.html, "spring/self"_fix_spring_self.html, "temp/berendsen"_fix_temp_berendsen.html, "temp/rescale"_fix_temp_rescale.html, "thermal/conductivity"_fix_thermal_conductivity.html, "tmd"_fix_tmd.html, "ttm"_fix_ttm.html, "viscosity"_fix_viscosity.html, "viscous"_fix_viscous.html, "wall/colloid"_fix_wall.html, "wall/gran"_fix_wall_gran.html, "wall/lj126"_fix_wall.html, "wall/lj93"_fix_wall.html, "wall/reflect"_fix_wall_reflect.html :tb(c=8,ea=c) These are fix styles contributed by users, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#2_3. "atc"_fix_atc.html, "imd"_fix_imd.html, "smd"_fix_smd.html :tb(c=4,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: "centro/atom"_compute_centro_atom.html, "cna/atom"_compute_cna_atom.html, "com"_compute_com.html, "coord/atom"_compute_coord_atom.html, "damage/atom"_compute_damage_atom.html, "displace/atom"_compute_displace_atom.html, "erotate/asphere"_compute_erotate_asphere.html, "erotate/sphere"_compute_erotate_sphere.html, "event/displace"_compute_event_displace.html, "group/group"_compute_group_group.html, +"gyration"_compute_gyration.html, "heat/flux"_compute_heat_flux.html, "ke"_compute_ke.html, "ke/atom"_compute_ke_atom.html, "msd"_compute_msd.html, "pe"_compute_pe.html, "pe/atom"_compute_pe_atom.html, "pressure"_compute_pressure.html, "reduce"_compute_reduce.html, "reduce/region"_compute_reduce.html, "stress/atom"_compute_stress_atom.html, "temp"_compute_temp.html, "temp/asphere"_compute_temp_asphere.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 :tb(c=6,ea=c) These are compute styles contributed by users, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#2_3. "ackland/atom"_compute_ackland_atom.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: "none"_pair_none.html, "hybrid"_pair_hybrid.html, "hybrid/overlay"_pair_hybrid.html, "airebo"_pair_airebo.html, "born/coul/long"_pair_born.html, "buck"_pair_buck.html, "buck/coul/cut"_pair_buck.html, "buck/coul/long"_pair_buck.html, "colloid"_pair_colloid.html, "coul/cut"_pair_coul.html, "coul/debye"_pair_coul.html, "coul/long"_pair_coul.html, "dipole/cut"_pair_dipole.html, "dpd"_pair_dpd.html, "dsmc"_pair_dsmc.html, "eam"_pair_eam.html, "eam/opt"_pair_eam.html, "eam/alloy"_pair_eam.html, "eam/alloy/opt"_pair_eam.html, "eam/fs"_pair_eam.html, "eam/fs/opt"_pair_eam.html, "gayberne"_pair_gayberne.html, "gayberne/gpu"_pair_gayberne.html, "gran/hertz/history"_pair_gran.html, "gran/hooke"_pair_gran.html, "gran/hooke/history"_pair_gran.html, "lj/charmm/coul/charmm"_pair_charmm.html, "lj/charmm/coul/charmm/implicit"_pair_charmm.html, "lj/charmm/coul/long"_pair_charmm.html, "lj/charmm/coul/long/opt"_pair_charmm.html, "lj/class2"_pair_class2.html, "lj/class2/coul/cut"_pair_class2.html, "lj/class2/coul/long"_pair_class2.html, "lj/cut"_pair_lj.html, "lj/cut/gpu"_pair_lj.html, "lj/cut/opt"_pair_lj.html, "lj/cut/coul/cut"_pair_lj.html, "lj/cut/coul/debye"_pair_lj.html, "lj/cut/coul/long"_pair_lj.html, "lj/cut/coul/long/tip4p"_pair_lj.html, "lj/expand"_pair_lj_expand.html, "lj/gromacs"_pair_gromacs.html, "lj/gromacs/coul/gromacs"_pair_gromacs.html, "lj/smooth"_pair_lj_smooth.html, "lj96/cut"_pair_lj96_cut.html, "lubricate"_pair_lubricate.html, "meam"_pair_meam.html, "morse"_pair_morse.html, "morse/opt"_pair_morse.html, "peri/pmb"_pair_peri_pmb.html, "reax"_pair_reax.html, "resquared"_pair_resquared.html, "soft"_pair_soft.html, "sw"_pair_sw.html, "table"_pair_table.html, "tersoff"_pair_tersoff.html, "tersoff/zbl"_pair_tersoff_zbl.html, "yukawa"_pair_yukawa.html, "yukawa/colloid"_pair_yukawa_colloid.html :tb(c=4,ea=c) These are pair styles contributed by users, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#2_3. "buck/coul"_pair_buck_coul.html, "cg/cmm"_pair_cmm.html, "cg/cmm/coul/cut"_pair_cmm.html, "cg/cmm/coul/long"_pair_cmm.html, "eam/cd"_pair_eam.html, "lj/coul"_pair_lj_coul.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: "none"_bond_none.html, "hybrid"_bond_hybrid.html, "class2"_bond_class2.html, "fene"_bond_fene.html, "fene/expand"_bond_fene_expand.html, "harmonic"_bond_harmonic.html, "morse"_bond_morse.html, "nonlinear"_bond_nonlinear.html, "quartic"_bond_quartic.html, "table"_bond_table.html :tb(c=4,ea=c,w=100) :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: "none"_angle_none.html, "hybrid"_angle_hybrid.html, "charmm"_angle_charmm.html, "class2"_angle_class2.html, "cosine"_angle_cosine.html, "cosine/delta"_angle_cosine_delta.html, "cosine/squared"_angle_cosine_squared.html, "harmonic"_angle_harmonic.html, "table"_angle_table.html :tb(c=4,ea=c,w=100) These are angle styles contributed by users, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#2_3. "cg/cmm"_angle_cmm.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: "none"_dihedral_none.html, "hybrid"_dihedral_hybrid.html, "charmm"_dihedral_charmm.html, "class2"_dihedral_class2.html, "harmonic"_dihedral_harmonic.html, "helix"_dihedral_helix.html, "multi/harmonic"_dihedral_multi_harmonic.html, "opls"_dihedral_opls.html :tb(c=4,ea=c,w=100) :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: "none"_improper_none.html, "hybrid"_improper_hybrid.html, "class2"_improper_class2.html, "cvff"_improper_cvff.html, "harmonic"_improper_harmonic.html :tb(c=4,ea=c,w=100) :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: "ewald"_kspace_style.html, "pppm"_kspace_style.html, "pppm/tip4p"_kspace_style.html :tb(c=4,ea=c,w=100) These are Kspace solvers contributed by users, which can be used if "LAMMPS is built with the appropriate package"_Section_start.html#2_3. "ewald/n"_kspace_style.html :tb(c=4,ea=c,w=100) diff --git a/doc/compute.html b/doc/compute.html index 0a54ec677..e245983a0 100644 --- a/doc/compute.html +++ b/doc/compute.html @@ -1,157 +1,158 @@ <HTML> <CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A> </CENTER> <HR> <H3>compute command </H3> <P><B>Syntax:</B> </P> <PRE>compute ID group-ID style args </PRE> <UL><LI>ID = user-assigned name for the computation <LI>group-ID = ID of the group of atoms to perform the computation on <LI>style = one of a list of possible style names (see below) <LI>args = arguments used by a particular style </UL> <P><B>Examples:</B> </P> <PRE>compute 1 all temp compute newtemp flow temp/partial 1 1 0 compute 3 all ke/atom </PRE> <P><B>Description:</B> </P> <P>Create a computation that will be performed on a group of atoms. Quantities calculated by a compute are instantaneous values, meaning they are calculated from information about atoms on the current timestep or iteration. There are two kinds of computes, "global" computes that calculate one or more values for the entire group of atoms, and "per-atom" computes that calculate one or more values for each atom in the group. The latter has the word "atom" in its style name. </P> <P>In LAMMPS, a "compute" can be used in several ways. The results of global computes can be output via the <A HREF = "thermo_style.html">thermo_style custom</A> or <A HREF = "fix_ave_time.html">fix ave/time</A> command. Or the values can be referenced in a <A HREF = "variable.html">variable equal</A> or <A HREF = "variable.html">variable atom</A> command. The results of computes that calculate a global temperature or pressure can be used by fixes that do thermostatting or barostatting and when atom velocities are created. </P> <P>The results of per-atom computes can be output via the <A HREF = "dump.html">dump custom</A> command or the <A HREF = "fix_ave_spatial.html">fix ave/spatial</A> command. Or the per-atom values can be time-averaged via the <A HREF = "fix_ave_atom.html">fix ave/atom</A> command and then output via the <A HREF = "dump.html">dump custom</A> or <A HREF = "fix_ave_spatial.html">fix ave/spatial</A> commands. Or the per-atom values can be referenced in a <A HREF = "variable.html">variable atom</A> command. Note that the value of per-atom computes will be 0.0 for atoms not in the specified compute group. </P> <P>See this <A HREF = "Section_howto.html#4_15">howto section</A> for a summary of various LAMMPS output options, many of which involve computes. </P> <P>The ID of a compute can only contain alphanumeric characters and underscores. </P> <P>The results of computes 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. <A HREF = "thermo_style.html">Thermodynamic output</A> will normalize extensive values depending on the "thermo_modify norm" setting. But if a compute value is accessed in another way, e.g. by a <A HREF = "variable.html">variable</A>, you may need to know whether it is an intensive or extensive value. See the doc page for individual computes for further info. </P> <P>LAMMPS creates its own global computes for thermodynamic output. Three computes are always created, named "thermo_temp", "thermo_press", and "thermo_pe", as if these commands had been invoked in the input script: </P> <PRE>compute thermo_temp all temp compute thermo_press all pressure thermo_temp compute thermo_pe all pe </PRE> <P>Additional computes for other quantities are created if the thermo style requires it. See the documentation for the <A HREF = "thermo_style.html">thermo_style</A> command. </P> <P>Fixes that calculate temperature or pressure, i.e. for thermostatting or barostatting, may also create computes. These are discussed in the documentation for specific <A HREF = "fix.html">fix</A> commands. </P> <P>In all these cases, the default computes can be replaced by computes defined by the user in the input script, as described by the <A HREF = "thermo_modify.html">thermo_modify</A> and <A HREF = "fix_modify.html">fix modify</A> commands. </P> <P>Properties of either a default or user-defined compute can be modified via the <A HREF = "compute_modify.html">compute_modify</A> command. </P> <P>Computes can be deleted with the <A HREF = "uncompute.html">uncompute</A> command. </P> <P>Code for new computes can be added to LAMMPS (see <A HREF = "Section_modify.html">this section</A> of the manual) and the results of their calculations accessed in the various ways described above. </P> <P>Each compute style has its own doc page which describes its arguments and what it does. Here is an alphabetic list of compute styles available in LAMMPS: </P> <UL><LI><A HREF = "compute_centro_atom.html">centro/atom</A> - centro-symmetry parameter for each atom <LI><A HREF = "compute_cna_atom.html">cna/atom</A> - common neighbor analysis (CNA) for each atom <LI><A HREF = "compute_com.html">com</A> - center-of-mass of group of atoms <LI><A HREF = "compute_coord_atom.html">coord/atom</A> - coordination number for each atom <LI><A HREF = "compute_damage_atom.html">damage/atom</A> - Peridynamic damage for each atom <LI><A HREF = "compute_displace_atom.html">displace/atom</A> - displacement of each atom <LI><A HREF = "compute_erotate_asphere.html">erotate/asphere</A> - rotational energy of aspherical particles <LI><A HREF = "compute_erotate_sphere.html">erotate/sphere</A> - rotational energy of spherical particles <LI><A HREF = "compute_event_displace.html">event/displace</A> - detect event on atom displacement <LI><A HREF = "compute_group_group.html">group/group</A> - energy/force between two groups of atoms +<LI><A HREF = "compute_gyration.html">gyration</A> - radius of gyration of group of atoms <LI><A HREF = "compute_heat_flux.html">heat/flux</A> - heat flux through a group of atoms <LI><A HREF = "compute_ke.html">ke</A> - translational kinetic energy <LI><A HREF = "compute_ke_atom.html">ke/atom</A> - kinetic energy for each atom <LI><A HREF = "compute_msd.html">msd</A> - mean-squared displacement of group of atoms <LI><A HREF = "compute_pe.html">pe</A> - potential energy <LI><A HREF = "compute_pe_atom.html">pe/atom</A> - potential energy for each atom <LI><A HREF = "compute_pressure.html">pressure</A> - total pressure and pressure tensor <LI><A HREF = "compute_reduce.html">reduce</A> - combine per-atom quantities into a single global value <LI><A HREF = "compute_reduce.html">reduce/region</A> - same as compute reduce, within a region <LI><A HREF = "compute_stress_atom.html">stress/atom</A> - stress tensor for each atom <LI><A HREF = "compute_temp.html">temp</A> - temperature of group of atoms <LI><A HREF = "compute_temp_asphere.html">temp/asphere</A> - temperature of aspherical particles <LI><A HREF = "compute_temp_com.html">temp/com</A> - temperature after subtracting center-of-mass velocity <LI><A HREF = "compute_temp_deform.html">temp/deform</A> - temperature excluding box deformation velocity <LI><A HREF = "compute_temp_partial.html">temp/partial</A> - temperature excluding one or more dimensions of velocity <LI><A HREF = "compute_temp_profile.html">temp/profile</A> - temperature excluding a binned velocity profile <LI><A HREF = "compute_temp_ramp.html">temp/ramp</A> - temperature excluding ramped velocity component <LI><A HREF = "compute_temp_region.html">temp/region</A> - temperature of a region of atoms <LI><A HREF = "compute_temp_sphere.html">temp/sphere</A> - temperature of spherical particles </UL> <P>There are also additional compute styles submitted by users which are included in the LAMMPS distribution. The list of these with links to the individual styles are given in the compute section of <A HREF = "Section_commands.html#3_5">this page</A>. </P> <P><B>Restrictions:</B> none </P> <P><B>Related commands:</B> </P> <P><A HREF = "uncompute.html">uncompute</A>, <A HREF = "compute_modify.html">compute_modify</A>, <A HREF = "fix_ave_atom.html">fix ave/atom</A>, <A HREF = "fix_ave_spatial.html">fix ave/spatial</A>, <A HREF = "fix_ave_time.html">fix ave/time</A> </P> <P><B>Default:</B> none </P> </HTML> diff --git a/doc/compute.txt b/doc/compute.txt index 0abdcf323..e8a5cc8ed 100644 --- a/doc/compute.txt +++ b/doc/compute.txt @@ -1,152 +1,153 @@ "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 compute command :h3 [Syntax:] compute ID group-ID style args :pre ID = user-assigned name for the computation group-ID = ID of the group of atoms to perform the computation on style = one of a list of possible style names (see below) args = arguments used by a particular style :ul [Examples:] compute 1 all temp compute newtemp flow temp/partial 1 1 0 compute 3 all ke/atom :pre [Description:] Create a computation that will be performed on a group of atoms. Quantities calculated by a compute are instantaneous values, meaning they are calculated from information about atoms on the current timestep or iteration. There are two kinds of computes, "global" computes that calculate one or more values for the entire group of atoms, and "per-atom" computes that calculate one or more values for each atom in the group. The latter has the word "atom" in its style name. In LAMMPS, a "compute" can be used in several ways. The results of global computes 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. The results of computes that calculate a global temperature or pressure can be used by fixes that do thermostatting or barostatting and when atom velocities are created. The results of per-atom computes can be output via the "dump custom"_dump.html command or the "fix ave/spatial"_fix_ave_spatial.html command. Or the per-atom values can be time-averaged via the "fix ave/atom"_fix_ave_atom.html command and then output via the "dump custom"_dump.html or "fix ave/spatial"_fix_ave_spatial.html commands. Or the per-atom values can be referenced in a "variable atom"_variable.html command. Note that the value of per-atom computes will be 0.0 for atoms not in the specified compute group. See this "howto section"_Section_howto.html#4_15 for a summary of various LAMMPS output options, many of which involve computes. The ID of a compute can only contain alphanumeric characters and underscores. The results of computes 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 depending on the "thermo_modify norm" setting. But if a compute value is accessed in another way, e.g. by a "variable"_variable.html, you may need to know whether it is an intensive or extensive value. See the doc page for individual computes for further info. LAMMPS creates its own global computes for thermodynamic output. Three computes are always created, named "thermo_temp", "thermo_press", and "thermo_pe", as if these commands had been invoked in the input script: compute thermo_temp all temp compute thermo_press all pressure thermo_temp compute thermo_pe all pe :pre Additional computes for other quantities are created if the thermo style requires it. See the documentation for the "thermo_style"_thermo_style.html command. Fixes that calculate temperature or pressure, i.e. for thermostatting or barostatting, may also create computes. These are discussed in the documentation for specific "fix"_fix.html commands. In all these cases, the default computes can be replaced by computes defined by the user in the input script, as described by the "thermo_modify"_thermo_modify.html and "fix modify"_fix_modify.html commands. Properties of either a default or user-defined compute can be modified via the "compute_modify"_compute_modify.html command. Computes can be deleted with the "uncompute"_uncompute.html command. Code for new computes can be added to LAMMPS (see "this section"_Section_modify.html of the manual) and the results of their calculations accessed in the various ways described above. Each compute style has its own doc page which describes its arguments and what it does. Here is an alphabetic list of compute styles available in LAMMPS: "centro/atom"_compute_centro_atom.html - centro-symmetry parameter for each atom "cna/atom"_compute_cna_atom.html - common neighbor analysis (CNA) for each atom "com"_compute_com.html - center-of-mass of group of atoms "coord/atom"_compute_coord_atom.html - coordination number for each atom "damage/atom"_compute_damage_atom.html - Peridynamic damage for each atom "displace/atom"_compute_displace_atom.html - displacement of each atom "erotate/asphere"_compute_erotate_asphere.html - rotational energy of aspherical particles "erotate/sphere"_compute_erotate_sphere.html - rotational energy of spherical particles "event/displace"_compute_event_displace.html - detect event on atom displacement "group/group"_compute_group_group.html - energy/force between two groups of atoms +"gyration"_compute_gyration.html - radius of gyration of group of atoms "heat/flux"_compute_heat_flux.html - heat flux through a group of atoms "ke"_compute_ke.html - translational kinetic energy "ke/atom"_compute_ke_atom.html - kinetic energy for each atom "msd"_compute_msd.html - mean-squared displacement of group of atoms "pe"_compute_pe.html - potential energy "pe/atom"_compute_pe_atom.html - potential energy for each atom "pressure"_compute_pressure.html - total pressure and pressure tensor "reduce"_compute_reduce.html - combine per-atom quantities into a single global value "reduce/region"_compute_reduce.html - same as compute reduce, within a region "stress/atom"_compute_stress_atom.html - stress tensor for each atom "temp"_compute_temp.html - temperature of group of atoms "temp/asphere"_compute_temp_asphere.html - temperature of aspherical particles "temp/com"_compute_temp_com.html - temperature after subtracting center-of-mass velocity "temp/deform"_compute_temp_deform.html - temperature excluding box deformation velocity "temp/partial"_compute_temp_partial.html - temperature excluding one or more dimensions of velocity "temp/profile"_compute_temp_profile.html - temperature excluding a binned velocity profile "temp/ramp"_compute_temp_ramp.html - temperature excluding ramped velocity component "temp/region"_compute_temp_region.html - temperature of a region of atoms "temp/sphere"_compute_temp_sphere.html - temperature of spherical particles :ul There are also additional compute styles submitted by users which are included in the LAMMPS distribution. The list of these with links to the individual styles are given in the compute section of "this page"_Section_commands.html#3_5. [Restrictions:] none [Related commands:] "uncompute"_uncompute.html, "compute_modify"_compute_modify.html, "fix ave/atom"_fix_ave_atom.html, "fix ave/spatial"_fix_ave_spatial.html, "fix ave/time"_fix_ave_time.html [Default:] none diff --git a/doc/compute_gyration.html b/doc/compute_gyration.html new file mode 100644 index 000000000..b3888a372 --- /dev/null +++ b/doc/compute_gyration.html @@ -0,0 +1,64 @@ +<HTML> +<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A> +</CENTER> + + + + + + +<HR> + +<H3>compute gyration command +</H3> +<P><B>Syntax:</B> +</P> +<PRE>compute ID group-ID gyration +</PRE> +<UL><LI>ID, group-ID are documented in <A HREF = "compute.html">compute</A> command +<LI>gyration = style name of this compute command +</UL> +<P><B>Examples:</B> +</P> +<PRE>compute 1 molecule gyration +</PRE> +<P><B>Description:</B> +</P> +<P>Define a computation that calculates the radius of gyration Rg of the +group of atoms, including all effects due to atoms passing thru +periodic boundaries. +</P> +<P>Rg is a measure of the size of the group of atoms, and is computed by +this formula +</P> +<CENTER><IMG SRC = "Eqs/compute_gyration.jpg"> +</CENTER> +<P>where M is the total mass of the group and Rcm is the center-of-mass +position of the group. +</P> +<P>IMPORTANT NOTE: The coordinates of an atom contribute to Rg in +"unwrapped" form, by using the image flags associated with each atom. +See the <A HREF = "dump.html">dump custom</A> command for a discussion of +"unwrapped" coordinates. See the Atoms section of the +<A HREF = "read_data.html">read_data</A> command for a discussion of image flags and +how they are set for each atom. You can reset the image flags +(e.g. to 0) before invoking this compute by using the <A HREF = "set.html">set +image</A> command. +</P> +<P><B>Output info:</B> +</P> +<P>This compute calculates a global scalar (Rg). This value can be used +by any command that uses a global scalar value from a compute as +input. See <A HREF = "Section_howto.html#4_15">this section</A> for an overview of +LAMMPS output options. +</P> +<P>The scalar value calculated by this compute is "intensive", meaning it +is independent of the number of atoms in the simulation. +</P> +<P><B>Restrictions:</B> none +</P> +<P><B>Related commands:</B> none +</P> +<P><B>Default:</B> none +</P> +</HTML> diff --git a/doc/compute_gyration.txt b/doc/compute_gyration.txt new file mode 100644 index 000000000..8cd5b445e --- /dev/null +++ b/doc/compute_gyration.txt @@ -0,0 +1,59 @@ +"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 + +compute gyration command :h3 + +[Syntax:] + +compute ID group-ID gyration :pre + +ID, group-ID are documented in "compute"_compute.html command +gyration = style name of this compute command :ul + +[Examples:] + +compute 1 molecule gyration :pre + +[Description:] + +Define a computation that calculates the radius of gyration Rg of the +group of atoms, including all effects due to atoms passing thru +periodic boundaries. + +Rg is a measure of the size of the group of atoms, and is computed by +this formula + +:c,image(Eqs/compute_gyration.jpg) + +where M is the total mass of the group and Rcm is the center-of-mass +position of the group. + +IMPORTANT NOTE: The coordinates of an atom contribute to Rg in +"unwrapped" form, by using the image flags associated with each atom. +See the "dump custom"_dump.html command for a discussion of +"unwrapped" coordinates. See the Atoms section of the +"read_data"_read_data.html command for a discussion of image flags and +how they are set for each atom. You can reset the image flags +(e.g. to 0) before invoking this compute by using the "set +image"_set.html command. + +[Output info:] + +This compute calculates a global scalar (Rg). This value can be used +by any command that uses a global scalar value from a compute as +input. See "this section"_Section_howto.html#4_15 for an overview of +LAMMPS output options. + +The scalar value calculated by this compute is "intensive", meaning it +is independent of the number of atoms in the simulation. + +[Restrictions:] none + +[Related commands:] none + +[Default:] none