Hi, First, the standard value is 0.25 and not 0.025.
For the dielectric constant, there was alreday some explanations here: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14936.html https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14875.html alpha_opt at V=V_exp means that the dielectric function (and alpha_opt) is calculated only at V_exp and then used for all other volumes. See also this: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15531.html No, it is not mandatory to do PBE calculation before YS-PBE0. Starting YS-PBE0 from PBE electron density (case.clmsum) may just help to reduce the number of SCF iterations with YS-PBE0. Of course it is possible to optimize lattice parameters with YS-PBE0. You just need to add the "-hf" option in the optimize.job file. What is not possible with YS-PBE0 is to optimize the position of atoms in the unit cell (because the forces are not implemented for YS-PBE0). FT On Saturday 2018-08-04 14:46, Dr. K. C. Bhamu wrote:
Date: Sat, 4 Aug 2018 14:46:02 From: Dr. K. C. Bhamu <kcbham...@gmail.com> Reply-To: A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at> To: A Mailing list for WIEN2k users <Wien@zeus.theochem.tuwien.ac.at> Subject: [Wien] regarding mixing parameter in hybrid calculations Dear Dr. Tran, In the recent past, I did some calculations using YS-PBE0 for MgO and results were well reproduced (wien2k Exercise). I just read your paper (J. Phys.: Condens. Matter 25 (2013)) and get to know that we can control the mixing parameter using various ways. 1) Standard value (0.025) 2) By fitting (alpa_opt) 3) alpa_opt (V=V_exp) I have queries for option 2 and 3 alpa: 2) If I am not wrong (after having a detailed search), the value of dielectric constant used to get alpa_opt is the value of dielectric constant from Rel(epsilon) at energy 0.013610 eV, right? 3) How to get alpa_opt at V-V_exp? My next query is: It is reported in the Wien2k exercise that to do YS-PBE0 calculations we need to do a simple PBE scf. So if we really need to perform PBE calculations before going to YS-PBE0, I am wondering how to use YS-PBE0 to optimize the lattice parameters and to get structural properties? Could you please advice me on my concerns? * in above text "_" means an underscore. regards
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