EPW Forum

Dear Experts,
I am running epw for bulk silicon just for testing, I have taken 8 wannier functions and proj(1)='si:sp3' in my calculation,however I am getting a large band gap here.My DFT bandgap is 0.62eV but in silicon_band.dat (from epw) the bandgap I am getting is 1.8 eV nearly.As I found 8 wannier function is enough for epw of silicon.Is there any error I am getting here?Do I need to change my projection to make the band gap similar to DFT.Please suggest.

Thanks and regards,
Anindya Bose

Dear Experts,
I have resolved this band gap issue by slightly changing my projection.Now everything looks good.I am having one more query.I am trying to calculate the a2f of silicon.I can notice that by keeping a fixed fine k and q grid if I increase degaussw and degaussq then only I am getting finite values.Is there any critical limit of degaussw and degaussq beyond which result will be incorrect?After increasing the smearing parameter ,I can observe a change in a2f values from 0 to finite.

Thanks and regards,
Anindya Bose