I want to test different exchange correlational functional on Magnesium silicide to investigate the electronic properties. For example, if I have the
POTCAR library for various pseudopotentials of Mg and Si where we can specify the type of functional from the title/header let's say PBE. How can I change this PBE to PW91 in INCAR to see the effect? The following screencast is my
INCAR for structure relaxation.