forked from lijiext/lammps
111 lines
3.8 KiB
Plaintext
111 lines
3.8 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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pair_style kim command :h3
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[Syntax:]
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pair_style kim virialmode model :pre
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virialmode = KIMvirial or LAMMPSvirial
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model = name of KIM model (potential) :ul
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[Examples:]
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pair_style kim KIMvirial model_Ar_P_Morse
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pair_coeff * * Ar Ar :pre
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[Description:]
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This pair style is a wrapper on the "Knowledge Base for Interatomic
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Models (KIM)"_https://openkim.org repository of interatomic potentials,
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so that they can be used by LAMMPS scripts.
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In KIM lingo, a potential is a "model" and a model contains both the
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analytic formulas that define the potential as well as the parameters
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needed to run it for one or more materials, including coefficients and
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cutoffs.
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The argument {virialmode} determines how the global virial is
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calculated. If {KIMvirial} is specified, the KIM model performs the
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global virial calculation (if it knows how). If {LAMMPSvirial} is
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specified, LAMMPS computes the global virial using its fdotr mechanism.
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The argument {model} is the name of the KIM model for a specific
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potential as KIM defines it. In principle, LAMMPS can invoke any KIM
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model. You should get an error or warning message from either LAMMPS
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or KIM if there is an incompatibility.
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Only a single pair_coeff command is used with the {kim} style which
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specifies the mapping of LAMMPS atom types to KIM elements. This is
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done by specifying N additional arguments after the * * in the
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pair_coeff command, where N is the number of LAMMPS atom types:
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N element names = mapping of KIM elements to atom types :ul
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As an example, imagine the KIM model supports Si and C atoms. If your
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LAMMPS simulation has 4 atom types and you want the 1st 3 to be Si,
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and the 4th to be C, you would use the following pair_coeff command:
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pair_coeff * * Si Si Si C :pre
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The 1st 2 arguments must be * * so as to span all LAMMPS atom types.
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The first three Si arguments map LAMMPS atom types 1,2,3 to Si as
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defined within KIM. The final C argument maps LAMMPS atom type 4 to C
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as defined within KIM. If a mapping value is specified as NULL, the
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mapping is not performed. This can only be used when a {kim}
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potential is used as part of the {hybrid} pair style. The NULL values
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are placeholders for atom types that will be used with other
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potentials.
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:line
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In addition to the usual LAMMPS error messages, the KIM library itself
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may generate errors, which should be printed to the screen. In this
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case it is also useful to check the kim.log file for additional error
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information. This file kim.log should be generated in the same
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directory where LAMMPS is running.
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To download, build, and install the KIM library on your system, see
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the lib/kim/README file. Once you have done this and built LAMMPS
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with the KIM package installed you can run the example input scripts
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in examples/kim.
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:line
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[Mixing, shift, table, tail correction, restart, rRESPA info]:
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This pair style does not support the "pair_modify"_pair_modify.html
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mix, shift, table, and tail options.
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This pair style does not write its information to "binary restart
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files"_restart.html, since KIM stores the potential parameters.
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Thus, you need to re-specify the pair_style and pair_coeff commands in
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an input script that reads a restart file.
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This pair style can only be used via the {pair} keyword of the
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"run_style respa"_run_style.html command. It does not support the
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{inner}, {middle}, {outer} keywords.
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:line
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[Restrictions:]
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This pair style is part of the KIM package. It is only enabled if
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LAMMPS was built with that package. See the "Making
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LAMMPS"_Section_start.html#start_3 section for more info.
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This current version of pair_style kim is compatible with the
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kim-api package version 1.6.0 and higher.
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[Related commands:]
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"pair_coeff"_pair_coeff.html
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[Default:] none
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