<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
font-size:10.5pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
text-indent:21.0pt;
font-size:10.5pt;
font-family:"Calibri",sans-serif;}
.MsoChpDefault
{mso-style-type:export-only;}
/* Page Definitions */
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:2068065856;
mso-list-type:hybrid;
mso-list-template-ids:577413316 -1 67698713 67698715 67698703 67698713 67698715 67698703 67698713 67698715;}
@list l0:level1
{mso-level-text:"%1\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:18.0pt;
text-indent:-18.0pt;}
@list l0:level2
{mso-level-number-format:alpha-lower;
mso-level-text:"%2\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:42.0pt;
text-indent:-21.0pt;}
@list l0:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
margin-left:63.0pt;
text-indent:-21.0pt;}
@list l0:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:84.0pt;
text-indent:-21.0pt;}
@list l0:level5
{mso-level-number-format:alpha-lower;
mso-level-text:"%5\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:105.0pt;
text-indent:-21.0pt;}
@list l0:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
margin-left:126.0pt;
text-indent:-21.0pt;}
@list l0:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:147.0pt;
text-indent:-21.0pt;}
@list l0:level8
{mso-level-number-format:alpha-lower;
mso-level-text:"%8\)";
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:168.0pt;
text-indent:-21.0pt;}
@list l0:level9
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
margin-left:189.0pt;
text-indent:-21.0pt;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Hi experts,</p><p class=MsoNormal> I came across a problem when I was doing variable-cell relaxations for the metal Gallium. </p><p class=MsoNormal>1) I started the relaxations using the experimental structure.</p><p class=MsoNormal>2) I chose the PBE xc functional and the Dojo-ONCV pseudopotential. </p><p class=MsoNormal>3) As the attached log files show, after several ionic steps, the b axis is shorten by near 0.8 angstrom and at the same time, the c axis is lengthen by near 0.6 angstrom. </p><p class=MsoNormal>4) I’ve tried to increase the ecutwfc to 130 Ry, but it didn’t improve at all.</p><p class=MsoNormal>5) I tried to use the ultrasoft pseudopotential, but things were not getting better.</p><p class=MsoNormal>6) I also used VASP to do the same thing and VASP gives the optimized lattice constants very similar to the experimental ones.</p><p class=MsoNormal>I’m very confused. Look forward to any suggestions and helps!</p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'><o:p> </o:p></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'>Thanks!</p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'><o:p> </o:p></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'>Bet wishes,</p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:0cm'>Xiaowei<span style='font-size:11.0pt'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal align=left style='text-align:left;background:white'><span style='font-family:SimSun;color:black'>------------------------------<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:SimSun;color:black;background:white'>Ph.D. Student Xiao-Wei Zhang</span><span style='font-size:11.0pt'><o:p></o:p></span></p><div><p class=MsoNormal style='background:white'><span style='font-family:SimSun;color:black'>ICQM, School of Physics, Peking University<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:SimSun;color:black'>Email: </span><span style='color:black'><a href="mailto:willzxw@pku.edu.cn"><span style='font-family:SimSun;color:#3894C1;text-decoration:none'>willzxw@pku.edu.cn</span></a></span><span style='font-family:SimSun;color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:SimSun;color:black'>------------------------------<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>