These example scripts can be run with the USER-CUDA package, assuming you built LAMMPS with the package. You can run any of the scripts as follows. You can also reset the x,y,z variables in the command line to change the size of the problem. With USER-CUDA on 1 GPU: lmp_machine -c on -sf cuda < in.cuda.melt.2.5 lmp_machine -c on -sf cuda < in.cuda.phosphate With USER-CUDA on 2 GPUs: mpirun -np 2 lmp_machine -c on -sf cuda -pk cuda 2 < in.cuda.melt.2.5 mpirun -np 2 lmp_machine -c on -sf cuda -pk cuda 2 < in.cuda.rhodo CPU-only: lmp_machine in.cuda.melt.2.5 mpirun -np 4 lmp_machine < in.cuda.melt.5.0 mpirun -np 8 lmp_machine < in.cuda.rhodo