Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, Thank you. I get values that are much closer to literature. Dae Kwang Jun On Thursday, 30 June 2016, Mostafa Youssef wrote: > Dear Dae Kwang Jun > > Equation (1) that you wrote is the correct one. > > And you are right bulk V_AlAs and bulk V_GaAs are

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun Equation (1) that you wrote is the correct one. And you are right bulk V_AlAs and bulk V_GaAs are obtained in a similar way as in the interface but you need bulk cells. Their values can be anything , positive or negative it does not matter and in fact they are arbitrary.

Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, Thank you for your reply. I am not sure whether I understand what it is meant by "where EVBM_AlAs is referred to bulk V_AlAs and EVBM_GaAs is referred to bulk V_GaAs." I am assuming that the complete formula is either (1) EVBM_offset = (EVBM_AlAs - bulk V_AlAs) - (EVMB_GaAs

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun In addition for each bulk calculation one needs to calculate the bulk average electrostatic potential. Then for each compound you refer its EVBM to the electrostatic potential calculated in its bulk (not yet the interface). Only then you can use the interface

Re: [Pw_forum] Band Offsets too large

Dear Mostafa Youssef, I believe that I did that. I am not sure whether we both have the same thing on mind, however. Here is what I did. I calculated the band structures for both AlAs and GaAs using pw.x with calculation = 'bands' after the scf calculations. The VB Maxima of AlAs and GaAs occur

Re: [Pw_forum] Band Offsets too large

Dear Dae Kwang Jun, You also need 2 bulk calculations for AlAs and GaAs to get their band edges with respect to to their bulk electrostatic potentials. Then you can use the interface potential to align the band edges of the two semiconductors. It looks like you missed this step. Mostafa

[Pw_forum] Band Offsets too large

Dear all, I tried to calculate the band offset for GaAs-AlAs. However, the valence band offsets that I am getting are too large. I used 6 unit cells of GaAs and 6 unit cells of AlAs stacked in the 001 direction. For the offset I used the potential line up method. I used pw.x pp.x average.x to