<div>Dear Rylin,</div><div><br></div><div>You have no correlation in your XC functional. I have never used the
Cohen-Wu
functional but from skimming the paper I think you should add the pbe correlation to your input file:<br></div><div>&XC_FUNCTIONAL<br> &GGA_X_WC<br> &END</div><div>
&GGA_C_PBE<br> &END
<br></div><div>&END XC_FUNCTIONAL</div><div><br></div><div>Please make sure to double check this!<br></div><div><br></div><div>Cheers,</div><div>Fabian<br></div><div class="gmail_quote"><div dir="auto" class="gmail_attr">On Wednesday, 22 December 2021 at 13:45:02 UTC+1 ruilin...@gmail.com wrote:<br/></div><blockquote class="gmail_quote" style="margin: 0 0 0 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Dear Prof.
Kühne<div><br>Thank you for your reply!<div>I modified my code by using a diagonalization method with a 4x4x4 Monkhorst-Pack k-point mesh. It indeed makes sense, however, there is still a big gap between the calculated cell parameters and the experimental results.</div><div>While using Cohen-Wu functional, the length of a and b axis seems acceptable, however, the length of c axis is about 4.6 angstroms. I think a difference of 0.6 angstroms is a little big. I also tried normal PBE functional. the calculated length of c axis is about 4.2 angstroms, still has a difference of about 0.2 angstrom from the experimental results. How can I improve my codes?</div><div>Looking forward to your reply!</div><div><br></div><div>Best regards,</div><div>Rylin Mao</div></div><div class="gmail_quote"><div dir="auto" class="gmail_attr">在2021年12月22日星期三 UTC+8 00:40:36<tkuehne> 写道：<br></div><blockquote class="gmail_quote" style="margin:0 0 0 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space">Try to use at least a 4x4x4 k-point mesh. <div><br></div><div>Best, </div><div>Thomas Kühne<br><div><br><blockquote type="cite"></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space"><div><div><blockquote type="cite"><div>Am 21.12.2021 um 16:46 schrieb 毛瑞麟 <<a rel="nofollow">ruilin...@gmail.com</a>>:</div><br></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space"><div><div><blockquote type="cite"><div>Dear CP2K Users:<div> I faced some problems while optimizing Tetragona BaTiO3 unit cell. I use direct cell optimization method, with Cohen-Wu Exchange correlation functionals. As described in literature, Cohen-Wu functional is the best functional which can be used in ferroelctric systems. However, the cell parameters after optimization EXTREMELY (a=b=4.30 angstroms, c=5.59 angstroms) diverge from cell parameters measured by experiments (a=b=3.99 angstroms, c=4.04 angstroms). All electron steps converge normally. </div><div> I also tried normal PBE functional and PBEsol functional, the cell parameters seemed far away from what is normal. </div><div> So can anyone tell me what's wrong with my codes or how can I modify my code?</div><div>Best regards</div><div><br></div></div></blockquote></div></div></div><div style="word-wrap:break-word;line-break:after-white-space"><div><div><blockquote type="cite"><div>
-- <br>
You received this message because you are subscribed to the Google Groups "cp2k" group.<br>
To unsubscribe from this group and stop receiving emails from it, send an email to <a rel="nofollow">cp2k+uns...@googlegroups.com</a>.<br>
To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/eb8becbc-612b-4032-a07b-053058194a17n%40googlegroups.com?utm_medium=email&utm_source=footer" rel="nofollow" target="_blank" data-saferedirecturl="https://www.google.com/url?hl=en-GB&q=https://groups.google.com/d/msgid/cp2k/eb8becbc-612b-4032-a07b-053058194a17n%2540googlegroups.com?utm_medium%3Demail%26utm_source%3Dfooter&source=gmail&ust=1640936986287000&usg=AFQjCNFRnKPRyiUg3ny-aIaxIATaIf4UWg">https://groups.google.com/d/msgid/cp2k/eb8becbc-612b-4032-a07b-053058194a17n%40googlegroups.com</a>.<br>
<span><0.out></span><span><1.inp></span><span><3-1.cell></span></div></blockquote></div><br></div><br><br><div>
<div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word;line-break:after-white-space"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word;line-break:after-white-space"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word;line-break:after-white-space"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word;line-break:after-white-space"><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">==============================</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">Thomas D. Kühne</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">Dynamics of Condensed Matter</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">Chair of Theoretical Chemistry</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">University of Paderborn</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">Warburger Str. 100</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">D-33098 Paderborn</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px">Germany</div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><a rel="nofollow">thomas...@upb.de</a></div><div style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-variant-east-asian:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><a href="tel:+49%205251%20605726" value="+495251605726" rel="nofollow" target="_blank">+49/(0)5251/60-5726</a></div></div></div></div></div>
</div>
<br></div></blockquote></div></blockquote></div>
<p></p>
-- <br />
You received this message because you are subscribed to the Google Groups "cp2k" group.<br />
To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>.<br />
To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/767a53d0-49b9-4ac7-8a9f-7d529ecf38d4n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/767a53d0-49b9-4ac7-8a9f-7d529ecf38d4n%40googlegroups.com</a>.<br />