BANDGAP

BANDGAP = COMPACT | WEIGHT | KPOINT
Default: BANDGAP = COMPACT

Description: BANDGAP determines the verbosity for reporting the bandgap to the OUTCAR file.

For semiconductor, the bandgap the direct and fundamental bandgap have a clear definition. For semimetals, the Fermi energy cuts through bands so the depending on the method one defines either a zero or a negative fundamental bandgap. For metals, defining a bandgap is not meaningful.

The bandgap of the system separates the occupied valence bands from the unoccupied conduction bands. Of particular interest are the fundamental bandgap between valence band maximum (VBM) and conduction band minimum (CBM) and the direct bandgap at a single k point.

BANDGAP controls how VASP reports the bandgap information. The following options exist:

BANDGAP=COMPACT

Uses Fermi weights to decide what valence and conduction bands are. Reports the VBM, CBM, and fundamental gap to the OUTCAR file.

BANDGAP=WEIGHT

Uses Fermi weights to decide what valence and conduction bands are. Provides a comprehensive report of all band extrema.

BANDGAP=KPOINT

Considers each k point individually to decide what valence and conduction bands are. Provides a comprehensive report of all band extrema.

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