Chimie Théorique » Opt'n Path

As VASP can perform NEB calculations, Path can use it in two ways: Serial or Parallel.

** Serial

In the Serial mode, Path uses Vasp to compute the energy and forces of each image separately (as it does for Gaussian for example).

Therefore, the INCAR file should not contain any references to the number of images (no IMAGES command!).

** Parallel

In the Parallel mode, Path uses VASP to compute at once the energies and forces for all the images (as VASP does for a NEB calculation).

Therefore, the INCAR file MUST contain the IMAGES command.

More, the directories 00, 01, ... should exist.

************* Home or Scracth ? *******

On our local cluster, it is adviced to perform the calculations on the /scratch directory that is local rather than on the /home that is mounted 

via NFS and is thus slow.

However, when doing so, we sometimes had troubles with VASP, and discovered that all files should be copied on the /scratch of all machines.

Therefore, the scripts are a bit tricky.

In case your computer center is similar to ours, we provide 2 SGE scripts:

run_Path_SGE_home: performs the VASP calculations in the /home directory

run_Path_SGE_scratch: creates the directories, copies the files and performs the VASP calculations in the local /scratch directories.