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--></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>