Hi Myung-Chul, in addition to Fabien's comments, I had a very positive experience with TB-mBJ also for semimetals. For instance, (HgCd)Te alloy has a negative band gap on the HgTe-reach side. TB-mBJ predicts the negative gap correctly (https://doi.org/10.1103/PhysRevB.90.115202), while PBE makes it too negative. With TB-mBJ we were able to get correct zero-gap (HgCd)Te composition.
Regarding topological materials: SnTe is an interesting material system. It has the experimental band gap of 0.18 eV. PBE overestimates (!) the band gap and yields 0.24 eV, while TB-mBJ gives a smaller (!) gap of 0.13 eV. I would definitely trust more TB-mBJ in this case. I hope it will help Oleg -- Oleg Rubel (PhD, PEng) Department of Materials Science and Engineering McMaster University JHE 359, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada Email: rub...@mcmaster.ca Tel: +1-905-525-9140, ext. 24094 Web: http://olegrubel.mcmaster ________________________________________ From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of Tran, Fabien <fabien.t...@tuwien.ac.at> Sent: Thursday, July 16, 2020 03:36 To: A Mailing list for WIEN2k users Subject: Re: [Wien] mBJ calculation for semimetallic system Hi, mBJ was proposed for the calculation of band gaps, which are more realistic than with LDA/PBE for nonmagnetic semiconductors and insulators, as well as antiferromagnetic systems. Concerning semimetals and topological insulators, I would recommend to search for results obtained with mBJ for systems which are similar to the ones you want to study. F. Tran From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of Aaron Jung <kangb...@gmail.com> Sent: Thursday, July 16, 2020 8:15 AM To: wien@zeus.theochem.tuwien.ac.at Subject: [Wien] mBJ calculation for semimetallic system Dear users and developers, Hello, I performed the mBJ calculation in a semimetallic system, but it has a tiny gap already. As considering SOC, the system becomes a semiconducting state. I have two questions. First, to investigate the Z2 indices on bulk system, I conduct the eigen parity for each TRIM points. In the mBJ calculation, the eigen parity is reliable? That is, can I accept the result of parity eigen value from the irrep calculation? Second, For LDA+mBJ calculation, Can I use the mBJ approach for semimatallic and nonmagnetic system? Thank you, Myung-Chul. ============================================================= Myung-Chul Jung Postdoctoral Researcher Electronic Structure Theory Group (E6-2, 4310) Department of Physics, Korea Advanced Institute of Science and Technology 291 Daehak-ro, Yuseong-gu, 34141, Korea ============================================================= _______________________________________________ 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