Dear Anupriya, I would first do a full optimization (vc-relax) in other code (VASP/QE) for such a large system and then using this fully optimized structure, I will do an ion relaxation (run_lapw .... -min) in Wien2k.
If you want to do everything using Wien2k, please follow Prof. Peter's response. Happy computing Regards Bhamu On Sat, Oct 23, 2021, 3:27 AM Peter Blaha <[email protected]> wrote: > A full optimization of a bigger triclinic structure is hardly possible > with WIEN2k. > > It depends a lot on what the purpose of your calculations is, but: > > a) Most importantly, optimize the position of the atoms using the > forces: run_lapw -min ... > > b) eventually I'd next do a volume optimization (x optimize, option 1) > Do not forget the -min switch in run_lapw, otherwise the results are > nonsense. Volume changes give the largest change in E-tot. > Note, that other separate options of x optimize are rather useless for > this purpose. One cannot optimize alpha,beta,gamma for fixed a,b,c. This > is nonsense. > > c) eventually you may use optimize_abc_lapw -t 3 ... > This optimizes a,b,c independently but simultaneously. Again don't > forget the -min switch. > > For such a large cell, such calculations can be very time consuming when > you do not use well adapted parameters (RKmax, k-points) and a good > parallelization strategy on a sufficient number of cores. > > Am 22.10.2021 um 04:54 schrieb Anupriya Nyayban: > > Dear users and experts, > > > > I have a triclinic structure (P1 space group) with lattice parameters > > a=18.508, b=39.835, c=40.199 Bohr; α = 119.701 ◦ , β = 103.309 ◦ , γ = > > 90.0 ◦. I have the following doubts > > 1) The volume obtained with these lattice parameters as well angles > > (with the formula for triclinic cell) is not the same as the volume > > (24823.466 Bohr^3) found in the scf file (VOL). > > 2) The mailing list suggests volume optimization by a) varying a, b, c > > while α, β, γ are constant; b) varying α, β, γ with fixed a, b, c. I > > have done volume optimization by varying volume with constant a:b:c. But > > I am not able to find the suitable switch for the case b) in the > > optimize.job script. > > Your valuable suggestion is highly appreciated!! > > > > Thank you!! > > -- > > With regards > > Anupriya Nyayban > > Ph.D. Scholar > > Department of Physics > > NIT Silchar > > > > _______________________________________________ > > 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 > > > > -- > -------------------------------------------------------------------------- > Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna > Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 > Email: [email protected] WIEN2k: http://www.wien2k.at > WWW: http://www.imc.tuwien.ac.at > ------------------------------------------------------------------------- > _______________________________________________ > 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 >
_______________________________________________ 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
