These are two different systems: CsPbI3 and CsPbCl3. I suggested to try CsPbCl3 since it works for it. Maybe there is a problem with the values for CsPbI3 in the paper.
________________________________________ From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of Peter Blaha <pbl...@theochem.tuwien.ac.at> Sent: Friday, December 6, 2019 9:07 AM To: wien@zeus.theochem.tuwien.ac.at Subject: Re: [Wien] spin-orbit (PBE and mBJ) for perovskites Note the different lattice parameters in the 2 previously attached struct files. Am 05.12.2019 um 22:39 schrieb Tran, Fabien: > Hi, > > Some time ago I did calculations on CsPbCl3 and I could reproduce > Jishi's results reasonably well except the one in the 1st column("GGA") > which is probably wrong. I got 0.70 eV (0.71 eV from Jishi) for > "GGA+SOC", 1.68 eV (1.59 eV from Jishi) for TB-mBJ and 2.86 eV (2.83 eV > from Jishi) for "present". The only special requirement that was needed > is a p1/2 LO on Pb. I used RKMAX=9 and de=10 in case.in1. The bug > reported here > > http://zeus.theochem.tuwien.ac.at/pipermail/wien/2019-November/029882.html > > is active but has very small effect of 0.01 eV for GGA+SOC. Try CsPbCl3 > instead (struct and inso are attached). > > FT > > ------------------------------------------------------------------------ > *From:* Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of > Mikhail Nestoklon <nestok...@mail.ru> > *Sent:* Thursday, December 5, 2019 8:21 PM > *To:* A Mailing list for WIEN2k users > *Subject:* [Wien] spin-orbit (PBE and mBJ) for perovskites > Dear wien2k community, > I plan to do some DFT calculation of inorganic perovskites using WIEN2k > (19.1 with some patches except the last one for RLO). > I’ve started from attempt to reproduce the values from Jishi et al., > JPCC 118, 28344 (2014), but can not get the numbers given in Table 2 > even for cubic CsPbI_3. The difference seem to stem from the spin-orbit. > What I did: > Using the file in attachment (I use the lattice constant given in table > 1 and R_MT indicated in the text) I do > $ init_lapw -b -vxc 13 -rkmax 9.0 -lvns 6 -fftfac 4 && x kgen (14x14x14) > && run_lapw -ec 0.00001 -cc 0.0001 > I use -lvns 6, the difference with the result using standard value is > small, in Jishi et al. it is mentioned that l_{max}=10 which is default, > assuming they might have meant lvns I tried lvns=10, the difference with > lvns=6 is close to zero. I also tried to put Pb p3/2 orbitals to core > (if I put P1/2 to valence the result is strange, but this is a separate > question) and see no difference. > For k-mesh I check the convergence and see that for 14x14x14 the total > energy convergence is below 1mRy and GAP is below 1 meV which is fine, > so I am using this k mesh. > Then I check the RKMAX convergence. For Rmt*Kmax =9 without spin-orbit I > get the same number as in Table 2, but I see that this number is not > fully converged: if I increase RKMAX further the total energy decreases > for 8mRy and gap increases for almost 6 meV. I find it acceptable to use > RKMAX=12: only then it is <1mRy and ~1meV for total energy and gap > respectively. The gap with these numbers is 1.329meV which is 5 meV > different from Table 2, this difference is probably acceptable. > However, when I switch on the spin-orbit, the difference is huge. With > the default values (I only increase llmax, however it does not change > much) I get GAP about 0.269meV, which is almost 4 times different from > the value given in Jishi et al. Table 2. As the SO value depends on de > (in case.in1), I increase this parameter and check the value of GAP and > also spin-orbit splitting of conduction and valence band (difference > between energies of Gamma_8 and Gamma_7 in R point). GAP and spin-orbit > in conduction band fully (below 1meV) converge only when de=15. Still, > the band gap is 0.259eV which is too far from value given in Jishi et al. > The RLO (I tried to add it on Cs, as for Pb it should be useless [1]) > does not help > With the same parameters I do the mBJ run (TB-mBJ). As expected, the gap > increases, but up to 0.722 eV which is two times different from the > value given in Jishi et al. > I did not try to change R_MT: I use the value given in their paper. > The fact that I do reproduce the number given for PBE without spin-orbit > indicates that I hardly did any mistake in the structure. However, the > difference in the numbers with spin-orbit is too large to be explained > by unconverged results, both on my and their side. Could you help me to > understand, how can I reproduce their results? > Thank you in advance. > Sincerely yours, > Mikhail Nestoklon > [1] > https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17828.html > > _______________________________________________ > 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 > -- -------------------------------------------------------------------------- Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 Email: bl...@theochem.tuwien.ac.at WIEN2k: http://www.wien2k.at WWW: http://www.imc.tuwien.ac.at/tc_blaha------------------------------------------------------------------------- _______________________________________________ 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 _______________________________________________ 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