Merge pull request #657 from lammps/snap-potentials

Note that some force field styles (pair, bond, angle, etc) do not

store their coefficient info in restart files.  Typically these are

many-body or tabulated potentials which read their parameters from

separate files.  In these cases you will need to re-specify the "pair

separate files.  In these cases you will need to re-specify the

"pair_coeff"_pair_coeff.html, "bond_coeff"_bond_coeff.html, etc

commands in your restart input script.  The doc pages for individual

force field styles mention if this is the case.  This is also true of

# DATE: 2017-09-18 CONTRIBUTOR: Chi Chen <chc273@eng.ucsd.edu> CITATION: C. Chen, Z. Deng, R. Tran, H. Tang, I.-H. Chu, S. P. Ong, "Accurate force field for molybdenum by machine learning large materials data" Physical Review Materials 1, 04 3603 (2017)

# Generated by Materials Virtual Lab

# Definition of SNAP potential.

pair_style snap

pair_coeff * * Mo_Chen_PRM2017.snapcoeff Mo Mo_Chen_PRM2017.snapparam Mo

# DATE: 2017-09-18 CONTRIBUTOR: Chi Chen <chc273@eng.ucsd.edu> CITATION: C. Chen, Z. Deng, R. Tran, H. Tang, I.-H. Chu, S. P. Ong, "Accurate force field for molybdenum by machine learning large materials data" Physical Review Materials 1, 04 3603 (2017)

# Generated by Materials Virtual Lab

1 31

Mo 0.5 1

-17.2757958404

0.00431015861472

0.0657685117891

0.477733335702

0.0152688837211

0.77559888196

0.284846429566

0.148804982644

0.0573702179736

0.19281989434

0.323441703578

0.101324335724

0.0139639846514

-0.0324444749083

0.0349797952779

0.0613023441282

0.0881078513046

0.118716074611

0.0069662975532

-0.0174658914685

-0.0178902177779

0.0195993756659

0.0719238160707

0.0344832661036

-0.0358616891662

-0.0292380783172

-0.0334933909866

0.00595462520243

0.0754556638328

-0.000972545258845

-0.0100170422751

# DATE: 2017-09-18 CONTRIBUTOR: Chi Chen <chc273@eng.ucsd.edu> CITATION: C. Chen, Z. Deng, R. Tran, H. Tang, I.-H. Chu, S. P. Ong, "Accurate force field for molybdenum by machine learning large materials data" Physical Review Materials 1, 04 3603 (2017)

# Generated by Materials Virtual Lab

rcutfac 4.615858

twojmax 6

# Demonstrate SNAP Ta potential

# Initialize simulation

variable nsteps index 100

variable nrep equal 4

variable a equal 3.160

units		metal

# generate the box and atom positions using a BCC lattice

variable nx equal ${nrep}

variable ny equal ${nrep}

variable nz equal ${nrep}

boundary	p p p

lattice         bcc $a

region		box block 0 ${nx} 0 ${ny} 0 ${nz}

create_box	1 box

create_atoms	1 box

mass 1 183.84

# choose potential

include Mo_Chen_PRM2017.snap

# Setup output

thermo		10

thermo_modify norm yes

# Set up NVE run

timestep 0.5e-3

neighbor 1.0 bin

neigh_modify once no every 1 delay 0 check yes

# Run MD

velocity all create 300.0 4928459

fix 1 all nve

run             ${nsteps}