Dear Giannozzi, Yes, the bandgap and peaks are the same with a shift in the axis x. However, all the tutorials I've watched and read showed me that, by using the Efermi to set the zero in the graph, the last peak of the valence band should end in the zero (as in my reference). But, in my case, it only occurs when I use 10x10x10 in the NSCF calculation and all other combinations of k-points gave me the second figure.
It is strange, for me, that only one value of k-points showed me the behavior that I was expecting, and that is the reason for my question. What is happening in my calculations to make the k-point 10x10x10 the only one that shows me a value of EFermi that corresponds to the "real" zero of the graph? Best wishes José Xavier Em terça-feira, 4 de janeiro de 2022 06:45:32 BRT, Paolo Giannozzi <[email protected]> escreveu: The two figures are exactly the same, only the origin of the x axis is shifted. Paolo On Tue, Jan 4, 2022 at 10:29 AM José Xavier via users <[email protected]> wrote: > Dear Nishidate, > > Thank you for your answer. > > I don't know if I understood... Could you explain me better what should I do, > please? > > I'm sending a figure of my DOS plotted using the HOMO and the EFermi as the > zero, respectively, to make my doubt clearer. > > I learned that I should use a "large" number of k-points to converge the > system. However, I only found the first figure when I used the 10x10x10 > k-points in the NSCF calculation, and 2x2x2, 4x4x4 or 6x6x6 in the SCF. When > I increased or decreased the k-points in the NSCF, it showed me the second > figure (that is different from the reference one). > > I tried to use the smearing occupations. In this test, the EFermi in SCF and > NSCF calculations were the same (2.74 eV), except when I used 10x10x10 > k-points in the NSCF. In this case, the EFermi was 2.74 in SCF and 1.04 eV in > the NSCF (it is the same value that I found previously as the HOMO in SCF > calculation). > > My main question is: Why is this 10x10x10 a "magic number"? > > Best wishes. > I wish you a happy new year. > > José Xavier > > >> >> >> Em qua., 29 29e dez. 29e 2021 às 18:22, Kazume NISHIDATE >> <[email protected]> escreveu: > > >> >> >> >> > > > > Dear Xavier > >> When I used the k-points 4x4x4 (SCF) and 8x8x8 (NSCF), the HOMO and >> EFermi were different, and using EFermi to subtract the values in the > > If the k-point mesh you selected covers the typical energy peaks of > the valence band maximum (VBM or the HOMO in your description) depends > on the shape of Brillouin zone (BZ) of your system. > > You should try to plot the band structure and assess the VBM and find > out its k-point location. If the k-point mesh you selected does not > cover the k-point, then the VBM peak will not contribute to your DOS > > plot. > > > > > > 敬具 西館 > > best regards > > > > [email protected] > > [email protected] > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 206, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
