Thank you Prof. Blaha It takes a bit of time, but at least I will understand either shrinkage or expansion of lattice is more energetically favorable.
Best regards Ali ________________________________ From: Wien <[email protected]> on behalf of Peter Blaha <[email protected]> Sent: 04 February 2020 15:20:20 To: [email protected] Subject: Re: [Wien] Volume optimization I'd guess you have experimental "a" lattice constants and in epitaxial growth you want to optimize "c" ??? Otherwise it does not work for hexagonal symmetry. It is a very difficult task: You have to edit case.struct yourself and change c, run a scf cycle and save. Make another change and run another scf cycle. Compare the energies and calculate yourself the optimal "c". There is no "click + core-dump" button for a 1D optimization. On 2/4/20 12:18 PM, Ali Baghizhadeh wrote: > Dear Wien2k users > > I am working on a hexagonal structure of YMnO3 epitaxial thin film. I > have experimental c-constant for different substrates, and I like to > estimate a-constant from DFT (assuming a unit cell similar to bulk one). > Looking at Optimize option, I could not figure out how to fix “c” and > relax “a”. Seems I can either optimize volume or c/a ratio or both, not > c or a alone. Is there any way to proceed with this calculation? Would > it be more rational if I relax atomic positions first, with experimental > c-constant and theoretical a-constant? > > Thank you in advance > > Ali > > > _______________________________________________ > 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 > -- P.Blaha -------------------------------------------------------------------------- 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/TC_Blaha -------------------------------------------------------------------------- _______________________________________________ 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
