Hello Ammar, This is a well known problem of LDA and GGA.
There are other methods that might circumvent this problem: LDA+U, meta-GGA, LDA-1/2, etc. Take a look in the following references (for LDA-1/2): - PRB 78, 125116 (2008); DOI: 10.1103/PhysRevB.78.125116 - Appl. Phys. Lett. 98, 151907 (2011); DOI: 10.1063/1.3576570 - AIP Advances 1, 032119 (2011); DOI: 10.1063/1.3624562 []'s, @mps On Sat, Jan 25, 2014 at 8:10 AM, Ammar Ahmad kirmani <[email protected] > wrote: > Hello Siesters :) > I hope you all are fine. I am trying to calculate band gap of semi > devices in optical limit. I cannot even get anything close B.G. of > germanium. I have checked all LDA and GGA methods but could not get any > better than .1 eV for .65 eV. Please help me if there is a way or I am > missing something. Any reference to this discussion? > Kind Regards > Ammar Kirmani >
