Both mBJ and unmodified BJ are potentials. For the 2nd second, I would just say: use the potential which leads to results that are the most pleasing.
On Fri, 15 Jan 2016, delamora wrote:
Thank you Dr. Tran, In the setting of the mBJ I used; init_mbj Which has different parametrizations of mBJ: 0: Original mBJ values (Tran,Blaha PRL102,226401) (default) 1: New parameterization (Koller etal, PRB85, 155109) 2: New parameterization for semiconductors (gaps up to 7 eV) 3: Unmodified BJ potential (Becke,Johnson J.Chem.Phys 124,221101 I used 0: Original mBJ values 3: Unmodified BJ potential So my question was; in option '3:' it is still a potential and not a functional and it does not work if :FER is not in the gap? This is because I have a system with Sm which has a peak in the gap and :FER is in that peak, so if the "Unmodified BJ potential" was more "flexible" than the "Original mBJ values" then I could use this option. I did the calculations again and I got for the gap: without BJ 5.05eV with mBJ 8.5eV with unmodified BJ 5.8eV but this time I did the things right and, for NaCl, I got :FER at the top of the valence band, which in earlier WIEN2k versions would move into the gap. So, my second question is; Which is better mBJ or 'unmodified BJ'? Pablo ________________________________________ If a system has a gap, then the Ef (:FER) is set at the top of the valence band maximum. Since there is for sure a gap in NaCl, whatever is the used potential, then I don't understand your statement about unmodified BJ. The value of :FER in case.scf should be equal to the valence band maximum (grep for :BAN00008: in case.scf). If not there is something wrong in your calculations. F. Tran On Thu, 14 Jan 2016, delamora wrote:WIEN2k users, I am trying the mBJ potential and the Unmodified BJ potential, so I took NaCl as an example, so I get for the gap; without BJ: 5eV mBJ: 8.2eV, and Ef is at the bottom of the gap Unmodified BJ: 6eV, Ef is not at the bottom of the gap With these 3 very different values which one is the best; mBJ or Unmodified BJ? I suppose that the Unmodified BJ is still a potential and cannot be used when Ef is not in the gap. Pablo I am using WIEN2k 14.2_______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
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