KPOINTS OPT
KPOINTS_OPT is an optional input file to perform an additional one-shot calculation after convergence. It has the same format as the KPOINTS file and is read automatically when present. VASP first performs a self-consistent calculation using the k points specified in the KPOINTS file and then performs an additional one-shot calculation to obtain the Kohn–Sham (KS) orbitals at the k points specified in the KPOINTS_OPT file.
| Important: The KPOINTS file must contain a uniform k mesh, when the KPOINTS_OPT file should be used afterward. |
This functionality is convenient for the following use cases among others:
- compute the band structure in one go,
- compute optical properties on a denser k mesh,
- compute the KS orbitals in a specific region of the BZ, e.g., to investigate a band crossing more closely.
The use of the KPOINTS_OPT file can be avoided by setting the LKPOINTS_OPT tag to .FALSE. in the INCAR file.
VASP writes the PROCAR_OPT file and corresponding fields in the vaspout.h5 file indicated by the keyword kpoints_opt.
| Mind: Available as of VASP 6.3.0. |