NBANDSEXACT
NBANDSEXACT = [integer]
Default: NBANDSEXACT | = -1 | for LALL_IN_ONE=.FALSE. |
= maximum number of plane waves | for LALL_IN_ONE=.TRUE. |
Description: NBANDSEXACT specifies the number of bands used in the all-in-one mode of many-body perturbation theory calculations.
Mind: available as of VASP.6.4.0 |
In the all-in-one mode, VASP automatically performs the necessary DFT steps prior to the many-body perturbation theory (MBPT) calculation, i.e. a DFT calculation with NBANDS, followed by an exact diagonalization of the Kohn-Sham Hamiltonian with NBANDSEXACT bands. Note, NBANDSEXACT is set by default to the maximum number of plane-waves given by the chosen energy cutoff for the orbitals ENCUT. In the all-in-one mode, the actual GW/RPA calculation is also performed with NBANDSEXACT bands. If NBANDS_WAVE is not set, all orbitals are written to WAVECAR, which potentially becomes huge in file size.
Tip: The NBANDS_WAVE tag can be used to limit the number of bands written to WAVECAR if LALL_IN_ONE=.TRUE.
The all-in-one mode is automatically enabled for ALGO=[EV]GW[0]R, RPA[R],ACFDT[R] if NBANDS is not set.
Related tags and articles
ALGO, NBANDS NBANDS_WAVE LALL_IN_ONE IALL_IN_ONE