"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

pair_style quip command :h3

[Syntax:]

pair_style quip :pre

[Examples:]

pair_style      quip
pair_coeff      * * gap_example.xml "Potential xml_label=GAP_2014_5_8_60_17_10_38_466" 14
pair_coeff      * * sw_example.xml "IP SW" 14 :pre

[Description:]

Style {quip} provides an interface for calling potential routines from
the QUIP package. QUIP is built separately, and then linked to
LAMMPS. The most recent version of the QUIP package can be downloaded
from GitHub:
"https://github.com/libAtoms/QUIP"_https://github.com/libAtoms/QUIP. The
interface is chiefly intended to be used to run Gaussian Approximation
Potentials (GAP), which are described in the following publications:
"(Bartok et al)"_#Bartok_2010 and "(PhD thesis of
Bartok)"_#Bartok_PhD.

Only a single pair_coeff command is used with the {quip} style that
specifies a QUIP potential file containing the parameters of the
potential for all needed elements in XML format. This is followed by a
QUIP initialization string. Finally, the QUIP elements are mapped to
LAMMPS atom types by specifying N atomic numbers, where N is the
number of LAMMPS atom types:

QUIP filename
QUIP initialization string
N atomic numbers = mapping of QUIP elements to atom types :ul

See the "pair_coeff"_pair_coeff.html doc page for alternate ways
to specify the path for the potential file.

A QUIP potential is fully specified by the filename which contains the
parameters of the potential in XML format, the initialization string,
and the map of atomic numbers.

GAP potentials can be obtained from the Data repository section of
"http://www.libatoms.org"_http://www.libatoms.org, where the
appropriate initialization strings are also advised. The list of
atomic numbers must be matched to the LAMMPS atom types specified in
the LAMMPS data file or elsewhere.

Two examples input scripts are provided in the examples/USER/quip
directory.

[Mixing, shift, table, tail correction, restart, rRESPA info]:

This pair style does not support the "pair_modify"_pair_modify.html
mix, shift, table, and tail options.

This pair style does not write its information to "binary restart
files"_restart.html, since it is stored in potential files.  Thus, you
need to re-specify the pair_style and pair_coeff commands in an input
script that reads a restart file.

This pair style can only be used via the {pair} keyword of the
"run_style respa"_run_style.html command.  It does not support the
{inner}, {middle}, {outer} keywords.

[Restrictions:]

This pair style is part of the USER-QUIP package.  It is only enabled
if LAMMPS was built with that package.  See the "Making
LAMMPS"_Section_start.html#start_3 section for more info.

QUIP potentials are parametrized in electron-volts and Angstroms and
therefore should be used with LAMMPS metal "units"_units.html.

QUIP potentials are generally not designed to work with the scaling
factors set by the "special_bonds"_special_bonds.html command.  The
recommended setting in molecular systems is to include all
interactions, i.e. to use {special_bonds lj/coul 1.0 1.0 1.0}. Scaling
factors > 0.0 will be ignored and treated as 1.0. The only exception
to this rule is if you know that your QUIP potential needs to exclude
bonded, 1-3, or 1-4 interactions and does not already do this exclusion
within QUIP. Then a factor 0.0 needs to be used which will remove such
pairs from the neighbor list. This needs to be very carefully tested,
because it may remove pairs from the neighbor list that are still
required.

Pair style {quip} cannot be used with pair style {hybrid}, only
with {hybrid/overlay} and only the {quip} substyle is applied to
all atom types.

[Related commands:]

"pair_coeff"_pair_coeff.html

:line

:link(Bartok_2010)

[(Bartok_2010)] AP Bartok, MC Payne, R Kondor, and G Csanyi, Physical
Review Letters 104, 136403 (2010).

:link(Bartok_PhD)
[(Bartok_PhD)] A Bartok-Partay, PhD Thesis, University of Cambridge,
(2010).
