[QE-users] Problem with Plotting Fermi Surfaces

[Shima Sharifi]

Hi,
I am calculating band structure and fermi surfaces for a narrow-gap semiconductor using LDA, full relativistic, NC PPs.
 When I plot band structure I see a band gap of about 0.04eV, but When I want to plot Fermi Surfaces using Xcrysden, I saw some overlap between Valance and Conduction band, there is some contribution from valance bands at Fermi level.

Could you please guide me what is the problem with that?

I follow the instruction in example02 for plotting Fermi surfaces for my optimized parameters and atomic positions:
First a SCF calculation, Then a non-SCF (calculation: nscf, dense grid without any shift and tetrahedral method) and then post-processing with fs.x.


Thank you so much!

Best,
Shima