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Fermi energy in the Band structure calculation

Posted: Mon Nov 02, 2009 3:05 pm
by zhichengzhong
Dear all

When I try to plot the band structure by following the manual,

Step (1) Do self-consistent calculation, setting ISMEAR = -5.
Here we can got one Fermi Energy.

Step(2) read the CHGCAR from self-consistent calculation, and do non-selfconsistent calculation, setting ISMEAR = 0, Linemode Kpoints.
Here we can got a different Fermi Energy.

My question is When I try to plot the bandstructure, which Fermi energy should I use.

Thanks

Zhicheng

Fermi energy in the Band structure calculation

Posted: Tue Nov 03, 2009 4:23 pm
by admin
how much do the Fermi energies differ?
please note that
1) the Fermi energy is defined as the Kohn-Sham energy of the highest occupied state and you certainly have a different k-point set for the band-structure run.
2) in 3D-periodic systems, there is no well-defined 0-level of the energy
please plot the band structure with respect to the Fermi level obtained in that run