lammps/examples/gpu

These are input scripts designed for use with the GPU package.

To run them, you must first build LAMMPS with the GPU package
installed, following the steps explained in Section 2.3 of
doc/Section_start.html and lib/gpu/README.  An overview of building
and running LAMMPS with the GPU package is given in Section 5.6 of
doc/Section_accelerate.html.  Note that you can choose the precision
at which computations are performed on the GPU in the build process.

Note that lines such as this in each of the input scripts:

package 	gpu force/neigh 0 1 1

are set for running on a compute node with 2 GPUs.  If you
have a single GPU, you should comment out the line, since
the default is 1 GPU per compute node.

The scripts can be run in the usual manner:

lmp_g++ < in.gpu.melt.2.5
lmp_g++ < in.gpu.melt.5.0
lmp_g++ < in.gpu.phosphate
lmp_g++ < in.gpu.rhodo

mpirun -np 4 lmp_g++ < in.gpu.melt.2.5
mpirun -np 4 lmp_g++ < in.gpu.melt.5.0
mpirun -np 4 lmp_g++ < in.gpu.phosphate
mpirun -np 4 lmp_g++ < in.gpu.rhodo

The first set of commmands will run a single MPI task using a single
GPU (even if you have 2 GPUs).

The second set of commands will run 4 MPI tasks, with 2 MPI tasks per
GPU (if you have 2 GPUs), or 4 MPI tasks per GPU (if you have a single
GPU).