forked from lijiext/lammps
195 lines
7.1 KiB
Plaintext
195 lines
7.1 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,Commands_all.html)
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:line
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pair_style born command :h3
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pair_style born/omp command :h3
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pair_style born/gpu command :h3
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pair_style born/coul/long command :h3
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pair_style born/coul/long/gpu command :h3
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pair_style born/coul/long/omp command :h3
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pair_style born/coul/msm command :h3
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pair_style born/coul/msm/omp command :h3
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pair_style born/coul/wolf command :h3
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pair_style born/coul/wolf/gpu command :h3
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pair_style born/coul/wolf/omp command :h3
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pair_style born/coul/dsf command :h3
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[Syntax:]
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pair_style style args :pre
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style = {born} or {born/coul/long} or {born/coul/msm} or {born/coul/wolf}
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args = list of arguments for a particular style :ul
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{born} args = cutoff
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cutoff = global cutoff for non-Coulombic interactions (distance units)
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{born/coul/long} args = cutoff (cutoff2)
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cutoff = global cutoff for non-Coulombic (and Coulombic if only 1 arg) (distance units)
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cutoff2 = global cutoff for Coulombic (optional) (distance units)
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{born/coul/msm} args = cutoff (cutoff2)
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cutoff = global cutoff for non-Coulombic (and Coulombic if only 1 arg) (distance units)
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cutoff2 = global cutoff for Coulombic (optional) (distance units)
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{born/coul/wolf} args = alpha cutoff (cutoff2)
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alpha = damping parameter (inverse distance units)
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cutoff = global cutoff for non-Coulombic (and Coulombic if only 1 arg) (distance units)
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cutoff2 = global cutoff for Coulombic (optional) (distance units)
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{born/coul/dsf} args = alpha cutoff (cutoff2)
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alpha = damping parameter (inverse distance units)
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cutoff = global cutoff for non-Coulombic (and Coulombic if only 1 arg) (distance units)
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cutoff2 = global cutoff for Coulombic (distance units) :pre
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[Examples:]
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pair_style born 10.0
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pair_coeff * * 6.08 0.317 2.340 24.18 11.51
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pair_coeff 1 1 6.08 0.317 2.340 24.18 11.51 :pre
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pair_style born/coul/long 10.0
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pair_style born/coul/long 10.0 8.
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pair_coeff * * 6.08 0.317 2.340 24.18 11.51
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pair_coeff 1 1 6.08 0.317 2.340 24.18 11.51 :pre
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pair_style born/coul/msm 10.0
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pair_style born/coul/msm 10.0 8.0
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pair_coeff * * 6.08 0.317 2.340 24.18 11.51
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pair_coeff 1 1 6.08 0.317 2.340 24.18 11.51 :pre
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pair_style born/coul/wolf 0.25 10.0
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pair_style born/coul/wolf 0.25 10.0 9.0
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pair_coeff * * 6.08 0.317 2.340 24.18 11.51
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pair_coeff 1 1 6.08 0.317 2.340 24.18 11.51 :pre
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pair_style born/coul/dsf 0.1 10.0 12.0
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pair_coeff * * 0.0 1.00 0.00 0.00 0.00
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pair_coeff 1 1 480.0 0.25 0.00 1.05 0.50 :pre
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[Description:]
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The {born} style computes the Born-Mayer-Huggins or Tosi/Fumi
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potential described in "(Fumi and Tosi)"_#FumiTosi, given by
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:c,image(Eqs/pair_born.jpg)
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where sigma is an interaction-dependent length parameter, rho is an
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ionic-pair dependent length parameter, and Rc is the cutoff.
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The styles with {coul/long} or {coul/msm} add a Coulombic term as
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described for the "lj/cut"_pair_lj.html pair styles. An additional
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damping factor is applied to the Coulombic term so it can be used in
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conjunction with the "kspace_style"_kspace_style.html command and its
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{ewald} or {pppm} of {msm} option. The Coulombic cutoff specified for
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this style means that pairwise interactions within this distance are
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computed directly; interactions outside that distance are computed in
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reciprocal space.
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If one cutoff is specified for the {born/coul/long} and
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{born/coul/msm} style, it is used for both the A,C,D and Coulombic
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terms. If two cutoffs are specified, the first is used as the cutoff
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for the A,C,D terms, and the second is the cutoff for the Coulombic
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term.
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The {born/coul/wolf} style adds a Coulombic term as described for the
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Wolf potential in the "coul/wolf"_pair_coul.html pair style.
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The {born/coul/dsf} style computes the Coulomb contribution with the
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damped shifted force model as in the "coul/dsf"_pair_coul.html style.
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Note that these potentials are related to the "Buckingham
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potential"_pair_buck.html.
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The following coefficients must be defined for each pair of atoms
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types via the "pair_coeff"_pair_coeff.html command as in the examples
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above, or in the data file or restart files read by the
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"read_data"_read_data.html or "read_restart"_read_restart.html
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commands, or by mixing as described below:
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A (energy units)
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rho (distance units)
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sigma (distance units)
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C (energy units * distance units^6)
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D (energy units * distance units^8)
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cutoff (distance units) :ul
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The second coefficient, rho, must be greater than zero.
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The last coefficient is optional. If not specified, the global A,C,D
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cutoff specified in the pair_style command is used.
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For {born/coul/long}, {born/coul/wolf} and {born/coul/dsf} no
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Coulombic cutoff can be specified for an individual I,J type pair.
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All type pairs use the same global Coulombic cutoff specified in the
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pair_style command.
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:line
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Styles with a {gpu}, {intel}, {kk}, {omp}, or {opt} suffix are
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functionally the same as the corresponding style without the suffix.
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They have been optimized to run faster, depending on your available
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hardware, as discussed on the "Speed packages"_Speed_packages.html doc
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page. The accelerated styles take the same arguments and should
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produce the same results, except for round-off and precision issues.
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These accelerated styles are part of the GPU, USER-INTEL, KOKKOS,
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USER-OMP and OPT packages, respectively. They are only enabled if
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LAMMPS was built with those packages. See the "Build
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package"_Build_package.html doc page for more info.
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You can specify the accelerated styles explicitly in your input script
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by including their suffix, or you can use the "-suffix command-line
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switch"_Run_options.html when you invoke LAMMPS, or you can use the
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"suffix"_suffix.html command in your input script.
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See the "Speed packages"_Speed_packages.html doc page for more
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instructions on how to use the accelerated styles effectively.
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:line
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[Mixing, shift, table, tail correction, restart, rRESPA info]:
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These pair styles do not support mixing. Thus, coefficients for all
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I,J pairs must be specified explicitly.
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These styles support the "pair_modify"_pair_modify.html shift option
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for the energy of the exp(), 1/r^6, and 1/r^8 portion of the pair
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interaction.
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The {born/coul/long} pair style supports the
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"pair_modify"_pair_modify.html table option to tabulate the
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short-range portion of the long-range Coulombic interaction.
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These styles support the pair_modify tail option for adding long-range
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tail corrections to energy and pressure.
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Thess styles writes thei information to binary "restart"_restart.html
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files, so pair_style and pair_coeff commands do not need to be
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specified in an input script that reads a restart file.
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These styles can only be used via the {pair} keyword of the "run_style
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respa"_run_style.html command. They do not support the {inner},
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{middle}, {outer} keywords.
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:line
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[Restrictions:]
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The {born/coul/long} style is part of the KSPACE package. It is only
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enabled if LAMMPS was built with that package. See the "Build
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package"_Build_package.html doc page for more info.
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[Related commands:]
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"pair_coeff"_pair_coeff.html, "pair_style buck"_pair_buck.html
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[Default:] none
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:line
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:link(FumiTosi)
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Fumi and Tosi, J Phys Chem Solids, 25, 31 (1964),
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Fumi and Tosi, J Phys Chem Solids, 25, 45 (1964).
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