I guess that is caused by wrong lattice parameters, with experimental values of a=3.638 AA and c=5.88 AA one has already with pure GGA a band gap of 1.4 eV (optical gap about 2 eV)
I wonder why a U of 9 eV should be needed to increase the gap by only 0.6eV (if the indirect gap is 2 eV), seems there is something ill defined. (Note that there are many experimental values given that are measured under pressure) Ciao Gerhard DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy: "I think the problem, to be quite honest with you, is that you have never actually known what the question is." ==================================== Dr. Gerhard H. Fecher Institut of Inorganic and Analytical Chemistry Johannes Gutenberg - University 55099 Mainz and Max Planck Institute for Chemical Physics of Solids 01187 Dresden ________________________________________ Von: Wien [[email protected]] im Auftrag von Laurence Marks [[email protected]] Gesendet: Dienstag, 28. Januar 2020 16:45 An: A Mailing list for WIEN2k users Betreff: Re: [Wien] Ghost band error in SnS2 continued.... I suggest looking into: a) Whether experimentally this is a direct or indirect band-gap material. If it is an indirect gap, what that value is. The number in case.scf2* is the "minimum gap", not the sometimes larger direct gap. Trust experiment, do not just follow what someone else did. b) Look at the DOS to see what the HOMO & LUMO states are, not just the gap. c) From b), look at what the +U is doing. Is it pushing the d-bands lower, or the S higher? Use some deep core state as a reference (not simply the Fermi energy). d) Try -eece. While it is similar to +U , it is not the same and might work better. e) Try forcing the d-states into the core. For this you would use a larger RMT and instead of -6 use ".985" for your case. This will then use dstart to handle the tails of the states that are being forced into the core. This might work, although you will probably need to add a d linearization energy at something like 1.5 Ryd to avoid getting fake d-states (and ghostbands). This is somewhat advanced. On Tue, Jan 28, 2020 at 8:36 AM shamik chakrabarti <[email protected]<mailto:[email protected]>> wrote: I want to simulate Li intercalation voltage in SnS2. But for that I need to simulate pristine SnS2 properly.... On Tue, Jan 28, 2020, 19:46 Laurence Marks <[email protected]<mailto:[email protected]>> wrote: Reducing the RMT by 30% is somewhat large. The key question is what are you trying to do? Reproducing a result with Vasp is not good science if that is your purpose. Without that information I doubt that anyone can provide useful advice _____ Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu<http://www.numis.northwestern.edu> On Tue, Jan 28, 2020, 08:11 shamik chakrabarti <[email protected]<mailto:[email protected]>> wrote: Dear Professor Laurence and wien2k users, with reference to my earlier mail on SnS2, I have checked the change in RMT (for avoiding Ghostband) with U and corresponding band gap. The details are as follows; U = 7 eV RMT reduction 6% Band gap = 1.460 eV U = 8 eV RMT reduction 15% Band gap= 1.475 eV U= 9 eV RMT reduction 30% Band gap = 1.512 eV I have not able to reproduce the band gap ~ 2.1 eV as computed earlier using Vasp (Phys. Chem. Chem. Phys., 2016, 18, 318). Also, whether 30% reduction of RMT is acceptable??? Looking forward to further guidance from you. with regards, [https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif] -- Dr. Shamik Chakrabarti Research Fellow Department of Physics Indian Institute of Technology Patna Bihta-801103 Patna Bihar, India _______________________________________________ Wien mailing list [email protected]<mailto:[email protected]> https://urldefense.proofpoint.com/v2/url?u=http-3A__zeus.theochem.tuwien.ac.at_mailman_listinfo_wien&d=DwICAg&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=SIzNJ8SCoOK36MOMLf8xb01v7QQ9LleWEu5C-yIOVUs&s=mBm3FBO9lfjzZbqAsqX0bzJJwxtVTbYiarbHKo0zFYM&e= SEARCH the MAILING-LIST at: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.mail-2Darchive.com_wien-40zeus.theochem.tuwien.ac.at_index.html&d=DwICAg&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=SIzNJ8SCoOK36MOMLf8xb01v7QQ9LleWEu5C-yIOVUs&s=PhRj2NuBCcAx1g6I1CXK9bska5vBg7-KKz2aV8DxR6U&e= _______________________________________________ Wien mailing list [email protected]<mailto:[email protected]> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<https://urldefense.proofpoint.com/v2/url?u=http-3A__zeus.theochem.tuwien.ac.at_mailman_listinfo_wien&d=DwMFaQ&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=pMgcf-lFISfKWN78azpiq4bxRQrEuWAN7bV4gMuckJg&s=A7RL8ZaevZNIlxeUZep8_W-r9QzdRoxWeAh1V5V-Bjk&e=> SEARCH the MAILING-LIST at: http://www.mail-archive.com/[email protected]/index.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.mail-2Darchive.com_wien-40zeus.theochem.tuwien.ac.at_index.html&d=DwMFaQ&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=pMgcf-lFISfKWN78azpiq4bxRQrEuWAN7bV4gMuckJg&s=2haq4drTXoq0qD9xIAS2EcBreoz5j9l_XHUu4XDro0A&e=> _______________________________________________ Wien mailing list [email protected]<mailto:[email protected]> https://urldefense.proofpoint.com/v2/url?u=http-3A__zeus.theochem.tuwien.ac.at_mailman_listinfo_wien&d=DwICAg&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=pMgcf-lFISfKWN78azpiq4bxRQrEuWAN7bV4gMuckJg&s=A7RL8ZaevZNIlxeUZep8_W-r9QzdRoxWeAh1V5V-Bjk&e= SEARCH the MAILING-LIST at: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.mail-2Darchive.com_wien-40zeus.theochem.tuwien.ac.at_index.html&d=DwICAg&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=pMgcf-lFISfKWN78azpiq4bxRQrEuWAN7bV4gMuckJg&s=2haq4drTXoq0qD9xIAS2EcBreoz5j9l_XHUu4XDro0A&e= -- Professor Laurence Marks Department of Materials Science and Engineering Northwestern University www.numis.northwestern.edu<http://www.numis.northwestern.edu/> Corrosion in 4D: www.numis.northwestern.edu/MURI<http://www.numis.northwestern.edu/MURI> Co-Editor, Acta Cryst A "Research is to see what everybody else has seen, and to think what nobody else has thought" Albert Szent-Gyorgi _______________________________________________ Wien mailing list [email protected] http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/[email protected]/index.html
