Dear Paolo and all users I want to relax the structures of tetragonal and cubic BaTiO3 (barium titanate) But when I use some pseudopotentials, I can not reach the correct lattice parameters. Unfortunately, I calculate a=4.100 to 4.200 for cubic structure of BaTiO3 but all articles reported that "a" is about 4.006 and my results are very different !!!!!!!!!!!!!! Also, for tetragonal structure a=3.800 to 3.900 and c/a=1.250 to 1.265 !!!!!!!!!!!!!! but this is reported in some articles, a=3.991 and c/a=1.011 !!!!!!!!!!!!!!!
I used some pseudopotentials such as pz (for PSLibrary, both rrkjus and kjpaw), pw91 (for PSLibrary, both rrkjus and kjpaw), relpw91 (for PSLibrary, both rrkjus and kjpaw), pw91 (for Vanderbilt, US) and .... !!!!!!!!!!!!! All these did not calculate correctly both lattice parameters and polarizations, unfortunately !!!!!!!!!!! Which pseudopotential is good for this job? give me some suggestions, please !!! In general, I am very disappointed to QE and pseudopotentials Thanks in advance Mojtaba Mirseraji Ph.D. Candidate, theoretical condensed matter physics Arak Univ. I.R.IRAN _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
