Merge pull request #2159 from akohlmey/potential-unit-tag

These are input scripts used to run versions of several of the

benchmarks in the top-level bench directory using the GPU accelerator

package.  The results of running these scripts on two different machines

(a desktop with 2 Tesla GPUs and the ORNL Titan supercomputer) are shown

on the "GPU (Fermi)" section of the Benchmark page of the LAMMPS WWW

site: lammps.sandia.gov/bench.

Examples are shown below of how to run these scripts.  This assumes

you have built 3 executables with the GPU package

installed, e.g.

lmp_linux_single

lmp_linux_mixed

lmp_linux_double

------------------------------------------------------------------------

To run on just CPUs (without using the GPU styles),

do something like the following:

mpirun -np 1 lmp_linux_double -v x 8 -v y 8 -v z 8 -v t 100 < in.lj

mpirun -np 12 lmp_linux_double -v x 16 -v y 16 -v z 16 -v t 100 < in.eam

The "xyz" settings determine the problem size.  The "t" setting

determines the number of timesteps.

These mpirun commands run on a single node.  To run on multiple

nodes, scale up the "-np" setting.

------------------------------------------------------------------------

To run with the GPU package, do something like the following:

mpirun -np 12 lmp_linux_single -sf gpu -v x 32 -v y 32 -v z 64 -v t 100 < in.lj

mpirun -np 8 lmp_linux_mixed -sf gpu -pk gpu 2 -v x 32 -v y 32 -v z 64 -v t 100 < in.eam

The "xyz" settings determine the problem size.  The "t" setting

determines the number of timesteps.  The "np" setting determines how

many MPI tasks (per node) the problem will run on.  The numeric

argument to the "-pk" setting is the number of GPUs (per node); 1 GPU

is the default.  Note that you can use more MPI tasks than GPUs (per

node) with the GPU package.

These mpirun commands run on a single node.  To run on multiple nodes,

scale up the "-np" setting, and control the number of MPI tasks per

node via a "-ppn" setting.

------------------------------------------------------------------------

If the script has "titan" in its name, it was run on the Titan

supercomputer at ORNL.

# bulk Cu lattice

units		metal

atom_style	atomic

lattice		fcc 3.615

region		box block 0 $x 0 $y 0 $z

create_box	1 box

create_atoms	1 box

pair_style	eam

pair_coeff	1 1 Cu_u3.eam

velocity	all create 1600.0 376847 loop geom

neighbor	1.0 bin

neigh_modify    every 1 delay 5 check yes

fix		1 all nve

timestep	0.005

thermo		50

run		$t

# bulk Cu lattice

newton          off

package         gpu force/neigh 0 0 1

processors      * * * grid numa

variable	x index 1

variable	y index 1

variable	z index 1

variable	xx equal 20*$x

variable	yy equal 20*$y

variable	zz equal 20*$z

units		metal

atom_style	atomic

lattice		fcc 3.615

region		box block 0 ${xx} 0 ${yy} 0 ${zz}

create_box	1 box

create_atoms	1 box

pair_style	eam/gpu

pair_coeff	1 1 Cu_u3.eam

velocity	all create 1600.0 376847 loop geom

neighbor	1.0 bin

neigh_modify    every 1 delay 5 check yes

fix		1 all nve

timestep	0.005

thermo		50

run             15

run		100

# 3d Lennard-Jones melt

units		lj

atom_style	atomic

lattice		fcc 0.8442

region		box block 0 $x 0 $y 0 $z

create_box	1 box

create_atoms	1 box

mass		1 1.0

velocity	all create 1.44 87287 loop geom

pair_style	lj/cut 2.5

pair_coeff	1 1 1.0 1.0 2.5

neighbor	0.3 bin

neigh_modify	delay 0 every 20 check no

fix		1 all nve

run		$t

# 3d Lennard-Jones melt

newton          off

package         gpu force/neigh 0 0 1

processors      * * * grid numa

variable	x index 1

variable	y index 1

variable	z index 1

variable	xx equal 20*$x

variable	yy equal 20*$y

variable	zz equal 20*$z

units		lj

atom_style	atomic

lattice		fcc 0.8442

region		box block 0 ${xx} 0 ${yy} 0 ${zz}

create_box	1 box

create_atoms	1 box

mass		1 1.0

velocity	all create 1.44 87287 loop geom

pair_style	lj/cut/gpu 2.5

pair_coeff	1 1 1.0 1.0 2.5

neighbor	0.3 bin

neigh_modify	delay 0 every 20 check no

fix		1 all nve

run             15

run		100