VASP executable and number of processes (parallelization)

There needs to be a working VASP installation on the machine where the calculation is run. Specify the exact command you would like to execute to run VASP

  • as the Command to execute VASP on the main VASP page in AMSinput, or

  • as the VASPExec input option to the VASP engine text input, or

  • through the VASP_COMMAND environment variable.

For example, set it to mpirun -n 4 vasp, if you use mpirun to launch VASP and would like to parallelize over 4 processes.

Note

The environment variable SCM_DISABLE_MPI must be set to 1. This is automatically done by AMSinput.

Tip

On some systems VASP may require specific environment variables which are overriden by AMS. If you are having problems running AMS via VASP, consider writing a shell script that wraps your VASP command within a new environment.

Open a terminal and run VASP the way you would normally run it. For example, you might use this command:

mpirun -np 4 vasp

If that is how you run VASP, then you can generate the “command to run VASP” using this command:

sh $AMSHOME/scripting/scm/external_engines/backends/_vasp/generate_run_vasp_script.sh mpirun -np 4 vasp

If successful, that will create a file called run_vasp.sh that sets the PATH, LD_LIBARY_PATH, an DYLD_LIBRARY_PATH environment variables to their current values.

Then specify the Command to run VASP as sh /path/to/run_vasp.sh (use the full absolute path).

Feel free to modify run_vasp.sh, for example to change the number of processors, or to set additional environment variables.