[Pw_forum] supercell

Giuseppe Mattioli giuseppe.mattioli at ism.cnr.it
Tue Oct 29 10:17:45 CET 2013

Dear Halima
DFT+U is indeed a possible solution in order to have decent IE and EA values and, therefore, something resembling a correct band gap. But you should 
obtain a reduced gap (something around 1.0 eV) also with your standard GGA approach, unless, and this is your case, you are simulating something VERY 
far from the GaN wurtzite structure... Open your file with a visualization program (e.g., xcrysden), and you will spot the problem at once. :-)

On Monday 28 October 2013 21:12:22 Halima Zaari wrote:
> dear Quantum espresso users
> i tried to compute GaN supercell with 56 atoms (attached file the dos and
> scf.out)
> the total dos of GaN has a mettalic behavior.if can someone to tell me is
> this correct and logic??
> thanks in advance

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