After the energy levels at the various kpoints have been computed, they are occupied with electrons according to their energy.
With the variable occupy_levels you can control the way the occupation numbers are computed.
occupy_levels normal occupy up to fermi level, which is common to all kpoints or occupy_levels fixed occupy at each kpoint separately, don't level out
Default: occupy_levels normal
You must specify the width of the gaussian smearing IN ELECTRON VOLT that is done to the energy levels when they are occupied in the flevel subroutine. For insulators, choose a very small number, say 0.001 eV.
Example:
gaussian_smearing 0.1 sets the width of the gaussian to 0.1 eV
Default: gaussian_smearing 0.05