forked from lijiext/lammps
97 lines
3.4 KiB
Plaintext
97 lines
3.4 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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fix shardlow command :h3
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[Syntax:]
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fix ID group-ID shardlow :pre
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ID, group-ID are documented in "fix"_fix.html command
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shardlow = style name of this fix command :ul
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[Examples:]
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fix 1 all shardlow :pre
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[Description:]
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Specifies that the Shardlow splitting algorithm (SSA) is to be used to
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integrate the DPD equations of motion. The SSA splits the integration
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into a stochastic and deterministic integration step. The fix
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{shardlow} performs the stochastic integration step and must be used
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in conjunction with a deterministic integrator (e.g. "fix
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nve"_fix_nve.html or "fix nph"_fix_nph.html). The stochastic
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integration of the dissipative and random forces is performed prior to
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the deterministic integration of the conservative force. Further
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details regarding the method are provided in "(Lisal)"_#Lisal and
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"(Larentzos)"_#Larentzos.
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The fix {shardlow} must be used with the "pair_style
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dpd/fdt"_pair_style.html or "pair_style
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dpd/fdt/energy"_pair_style.html command to properly initialize the
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fluctuation-dissipation theorem parameter(s) sigma (and kappa, if
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necessary).
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Note that numerous variants of DPD can be specified by choosing an
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appropriate combination of the integrator and "pair_style
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dpd/fdt"_pair_style.html command. DPD under isothermal conditions can
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be specified by using fix {shardlow}, fix {nve} and pair_style
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{dpd/fdt}. DPD under isoenergetic conditions can be specified by
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using fix {shardlow}, fix {nve} and pair_style {dpd/fdt/energy}. DPD
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under isobaric conditions can be specified by using fix shardlow, fix
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{nph} and pair_style {dpd/fdt}. DPD under isoenthalpic conditions can
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be specified by using fix shardlow, fix {nph} and pair_style
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{dpd/fdt/energy}. Examples of each DPD variant are provided in the
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examples/USER/dpd directory.
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:line
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[Restrictions:]
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This fix is only available if LAMMPS is built with the USER-DPD
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package. See the "Making LAMMPS"_Section_start.html#start_3 section
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for more info.
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This fix is currently limited to orthogonal simulation cell
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geometries.
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This fix must be used with an additional fix that specifies time
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integration, e.g. "fix nve"_fix_nve.html or "fix nph"_fix_nh.html.
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The Shardlow splitting algorithm requires the sizes of the sub-domain
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lengths to be larger than twice the cutoff+skin. Generally, the
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domain decomposition is dependant on the number of processors
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requested.
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[Related commands:]
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"pair_style dpd/fdt"_pair_dpd_fdt.html, "fix eos/cv"_fix_eos_cv.html
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[Default:] none
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:line
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:link(Lisal)
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[(Lisal)] M. Lisal, J.K. Brennan, J. Bonet Avalos, "Dissipative
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particle dynamics as isothermal, isobaric, isoenergetic, and
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isoenthalpic conditions using Shardlow-like splitting algorithms.",
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J. Chem. Phys., 135, 204105 (2011).
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:link(Larentzos)
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[(Larentzos)] J.P. Larentzos, J.K. Brennan, J.D. Moore, M. Lisal and
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W.D. Mattson, "Parallel Implementation of Isothermal and Isoenergetic
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Dissipative Particle Dynamics Using Shardlow-Like Splitting
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Algorithms", Comput. Phys. Commun., 185, 1987-1998 (2014).
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:link(Larentzos)
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[(Larentzos)] J.P. Larentzos, J.K. Brennan, J.D. Moore, and
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W.D. Mattson, "LAMMPS Implementation of Constant Energy Dissipative
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Particle Dynamics (DPD-E)", ARL-TR-6863, U.S. Army Research
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Laboratory, Aberdeen Proving Ground, MD (2014).
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