<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1426170363317_18341">you should use</div><div id="yui_3_16_0_1_1426170363317_18365"><br></div><div id="yui_3_16_0_1_1426170363317_18192">Ba_lda_v1.uspp.F.UPF <br></div><div id="yui_3_16_0_1_1426170363317_18191">Ti_lda_v1.uspp.F.UPF</div><div id="yui_3_16_0_1_1426170363317_18342">O_lda_v1.2.uspp.F.UPF<br></div><div id="yui_3_16_0_1_1426170363317_18190"><span></span></div> <div class="qtdSeparateBR"><br><br></div><div style="display: block;" class="yahoo_quoted"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"> <font face="Arial" size="2"> On Thursday, March 12, 2015 9:45 PM, Mojtaba Mirseraji <quantum.pwscf@gmail.com> wrote:<br> </font> </div> <br><br> <div class="y_msg_container">Dear Paolo and all users<br><br>I want to relax the structures of tetragonal and cubic BaTiO3 (barium titanate)<br>But when I use some pseudopotentials, I can not reach the correct<br>lattice parameters.<br>Unfortunately, I calculate a=4.100 to 4.200 for cubic structure of<br>BaTiO3 but all articles reported that "a" is about 4.006 and my<br>results are very different !!!!!!!!!!!!!!<br>Also, for tetragonal structure a=3.800 to 3.900 and c/a=1.250 to 1.265<br>!!!!!!!!!!!!!!<br>but this is reported in some articles, a=3.991 and c/a=1.011 !!!!!!!!!!!!!!!<br><br>I used some pseudopotentials such as pz (for PSLibrary, both rrkjus<br>and kjpaw), pw91 (for PSLibrary, both rrkjus and kjpaw), relpw91 (for<br>PSLibrary, both rrkjus and kjpaw), pw91 (for Vanderbilt, US) and ....<br>!!!!!!!!!!!!!<br>All these did not calculate correctly both lattice parameters and<br>polarizations, unfortunately !!!!!!!!!!!<br><br>Which pseudopotential is good for this job? give me some suggestions, please !!!<br>In general, I am very disappointed to QE and pseudopotentials<br><br>Thanks in advance<br><br>Mojtaba Mirseraji<br>Ph.D. Candidate, theoretical condensed matter physics<br>Arak Univ.<br>I.R.IRAN<br>_______________________________________________<br>Pw_forum mailing list<br><a ymailto="mailto:Pw_forum@pwscf.org" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br><a href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a><br><br><br></div> </div> </div> </div> </div></body></html>