# Homework Help: Understanding INCAR file of VASP

1. Jan 29, 2014

### physicsjn

1. The problem statement, all variables and given/known data
Hi! Greetings! I am studying how to use VASP or the Vienna Ab-initio Simulation Package. I'm starting to study the parameters in the INCAR file first.

According to the online manual, the ISMEAR parameter is one of those that are recommended to be manually set. The ISMEAR definition is as follows:

ISMEAR determines how the partial occupancies $f_{n{\bf k}}$ are set for each orbital.

Questions: Are orbitals here defined as the most like area where electrons can be found (as taught in our chemistry)? Also, I don't really understand what "partial occupancies" mean.

Thank you very much.

physicsjn

Last edited: Jan 29, 2014