VBM and CBM position in HSE06 calculation

masoud37

Dear Admin,
I hope this message finds you well.
I did an HSE06 calculation to find the band gap in a 2D material.
I got the value of 1.4 eV for the band gap, but VBM and CBM positions are not correct in the output of CRYSTAL:
TOP OF VALENCE BANDS - BAND 15; K 1; EIG -8.7684392E-01 AU
BOTTOM OF VIRTUAL BANDS - BAND 16; K 48; EIG -2.2555491E-01 AU
Can you help me solving this problem in this case?
I have attached the input and output files.INPUT.d12 output.out

Thank you in advance,
Masoud

eascrizzi

Hi masoud37!

This is because you selected LEVSHIFT in your input. Try to restart the calculation without it or plot the band structure to see the correct value of the gap.

Hope it helps,
Eleonora

masoud37

eascrizzi said in VBM and CBM position in HSE06 calculation:

lot the band structure to see the correct value of the gap.

Thank you for your reply.
So, for semiconductors, LEVELSHIFT should not be added?

Best regards,
Masoud

eascrizzi

You can add it and sometimes it helps with the convergence but consider that the energies of the occupied orbitals are in fact shifted of the value you selected. If you want the correct value you can restart the calculation with GUESSP or plot a band structure.

Cheers,
Eleonora

masoud37

eascrizzi Thank you for your help.