Dear Endale,
The GBRV paper says, "Both the AE calculations and the pseudopotential constructions were scalar-relativistic, i.e., without spin–orbit interactions.". Hence, no. You might try making your own SO PPs using GBRV input files for Vanderbilt code, but as long as they optimized the recipes for SO-free calculations, the result might not be good. Best regards. Andrii W dniu 2020-10-20 05:12, ENDALE ABEBE napisał: > Dear Andrii Shyichuk > > Thank you for this clear explanation. I remember, I did two EOS calculations: > one with pseudopotential from http://physics.rutgers.edu/gbrv > the other from QE website; the later did not give me a smooth curve Now > thanks to you I have come to understand the reason. > > By the way, is it possible to use the pseudopotential obtained from > http://physics.rutgers.edu/gbrv for a calculation that includes > spin-orbit-coupling? > > With Kind Regards > > On Mon, Oct 19, 2020 at 1:19 AM Andrii Shyichuk > <andrii.shyic...@chem.uni.wroc.pl> wrote: > > Dear Endale, > > Using values smaller than recommended might result in errors going > unpredictably high. > In your case, using e.g. 40/400 instead of 45/455 could happen to be fine (or > not), but 30/300 is most likely bad. > > In order to check it, try a few calculations with different cutoffs. As the > cutoff goes up, band gap should approach some value. > As the cutoff goes down, the point of rapid change in the values is where > things get bad. > Same goes for DOS, if it starts to change at lower cutoffs - bad. > > Another thing to check is energy-volume curve (equation of state, EOS), which > should be smooth. > If it's not - the basis is probably too low. > And, it's minimum should converge with the increasing cutoffs. > > I recommend looking into GBRV pseudopotentials (optimized for about 40 Ry > cutoff) http://dx.doi.org/10.1016/j.commatsci.2013.08.053. > > Finally, check your basis on some known materials that contain the same > elements as your material of interest. > > Best regards. > Andrii Shyichuk > > W dniu 2020-10-20 02:10, ENDALE ABEBE napisał: > > Dear Expertise > > Let me say I am calculating the energy bandgap of a semiconductor, which > doesn't have reported value in literature. > What is the parameter that I need to check to say the ecutwfc/ecutrho is > sufficient and the value ot energy bandgap is correct? > > Thank you for your support > > With Best Regards > > On Tue, Oct 13, 2020 at 1:06 AM Paolo Giannozzi <p.gianno...@gmail.com> > wrote: > > As long as your cutoffs are sufficiently good to get the desired accuracy on > the targeted properties, there is no problem. The cutoffs suggested in the PP > file are on the safe side and thus quite high, if I remember correctly. > > Paolo > > On Mon, Oct 12, 2020 at 2:56 PM ENDALE ABEBE <end...@gmail.com> wrote: > > Dear Expertise > > The suggested values of the ecutrho and ecutwfc are making my calculation > expensive. For instance, in the pseudo potential file of Bi, > Bi.pbe-dn-kjpaw_psl.1.0.0.UPF [1], these are: > > Suggested minimum cutoff for wavefunctions: 45. Ry > Suggested minimum cutoff for charge density: 455. Ry > Is there any problem if I use less values than these as much as the total > energy of the system converges? > > Thank you in advance for your response. > > With Regards > > -- > > Endale Abebe > Program coordinator and Lecturer > Faculty of Materials Science and Engineering > Jimma Institute of Technology > Jimma University > > P.O.Box 378, Jimma, Ethiopia > Mobile: +251921381598 _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu [2]) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users > > -- > > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu [2]) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users -- Endale Abebe Program coordinator and Lecturer Faculty of Materials Science and Engineering Jimma Institute of Technology Jimma University P.O.Box 378, Jimma, Ethiopia Mobile: +251921381598 _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu [2]) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu [2]) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users -- Endale Abebe Program coordinator and Lecturer Faculty of Materials Science and Engineering Jimma Institute of Technology Jimma University P.O.Box 378, Jimma, Ethiopia Mobile: +251921381598 _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu [2]) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users Links: ------ [1] https://www.quantum-espresso.org/upf_files/Bi.pbe-dn-kjpaw_psl.1.0.0.UPF [2] http://www.max-centre.eu
_______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
