KPOINTS OPT: Difference between revisions

Revision as of 08:06, 17 January 2022

KPOINTS_OPT is an optional input file to perform an additional one-shot calculation after self-consistency is reached. The format is the same as for the KPOINTS file. 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 orbitals and eigenenergies 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.

KPOINTS_OPT is read automatically when present. To avoid this, set LKPOINTS_OPT=.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.

Related tags and sections

KPOINTS, KSPACING

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-{{FILE|KPOINTS_OPT}} is an optional input file to perform an additional one-shot calculation after convergence. It has the same format as the {{FILE|KPOINTS}} file and is read automatically when present. VASP first performs a self-consistent calculation using the '''k''' points specified in the {{FILE|KPOINTS}} file and then performs an additional one-shot calculation to obtain the Kohn&ndash;Sham (KS) orbitals at the '''k''' points specified in the {{FILE|KPOINTS_OPT}} file.
+{{FILE|KPOINTS_OPT}} is an optional input file to perform an additional one-shot calculation after self-consistency is reached. The format is the same as for the {{FILE|KPOINTS}} file. VASP first performs a self-consistent calculation using the '''k''' points specified in the {{FILE|KPOINTS}} file and then performs an additional one-shot calculation to obtain the Kohn&ndash;Sham orbitals and eigenenergies at the '''k''' points specified in the {{FILE|KPOINTS_OPT}} file.
 {{NB|important| The {{FILE|KPOINTS}} file must contain a uniform '''k''' mesh, when the {{FILE|KPOINTS_OPT}} file should be used afterward.}}
-This functionality is convenient for the following use cases among others:
+{{FILE|KPOINTS_OPT}} is read automatically when present. To avoid this, set {{TAG|LKPOINTS_OPT}}<code>=.FALSE.</code> in the {{FILE|INCAR}} file.
-* 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 {{FILE|KPOINTS_OPT}} file can be avoided by setting the {{TAG|LKPOINTS_OPT}} tag to <code>.FALSE.</code> in the {{FILE|INCAR}} file.
 VASP writes the {{FILE|PROCAR_OPT}} file and corresponding fields in the {{FILE|vaspout.h5}} file indicated by the keyword ''kpoints_opt''.
 {{NB|mind| Available as of VASP 6.3.0.}}