# VASP激发态INCAR

for non spin polarization

if

nelect=8
nbands=8
nkpts=1

say we want to occupy the first 3 bands, leaving the following 2 half occupied and the remaining empty

FERWE = 3*1 2*0.5 3*0

for spin polarization

FERWE = 5*1 3*0 (spin up)
FERDO = 3*1 5*0 (spin down)

In the case where there is more than one irreducible kpoint

for instance NKPTS = 3

no spin

FERWE = 3*1 2*0.5 3*0 3*1 2*0.5 3*0 3*1 2*0.5 3*0 i.e. repeats the definition of occupation you want for each k-point

spin

FERWE = 5*1 3*0 5*1 3*0 5*1 3*0 (spin up)
FERDO = 3*1 5*0 3*1 5*0 3*1 5*0 (spin down)

http://cms.mpi.univie.ac.at/vasp-forum/viewtopic.php?t=358&p=11864

http://cms.mpi.univie.ac.at/vasp-forum/viewtopic.php?t=10903

https://cms.mpi.univie.ac.at/vasp-forum/viewtopic.php?t=10207

https://wiki.kfki.hu/nano/Easy_manual_occupancy_of_Kohn-Sham_levels_with_FERWE_and_FERDO