<div dir="ltr">Dear <span style="color: rgb(0, 0, 0);" class="HOEnZb">IYAD I. AL-QASIR</span><br><br>1. Reduce the alpha_mix(1) by default 0.7, e.g. to 0.4.<br>2. If it doesn't work, open PH/phcom.f90 and change<br>
INTEGER, PARAMETER :: maxter = 100<br>
to something larger. ***Then recompile the<br>
code***.<br><br><div class="gmail_quote">On Wed, Nov 23, 2011 at 7:39 PM, IYAD AL-QASIR <span dir="ltr"><<a href="mailto:iyad.ne@gmail.com">iyad.ne@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="gmail_quote">Hello,<br>I am trying to calculate the phonon dispersion relations and phonon density of states of UO2.<br>Please find the attached files<span style="color:rgb(0,0,0)"><a href="http://UO2.scf.in" target="_blank">UO2.scf.in</a></span><span style="color:rgb(0,0,0)"> </span>and <a href="http://UO2.ph.in" target="_blank">UO2.ph.in</a><br>
<br>The calculations assume GGA and include spin-polarized effects.<br clear="all"><br>There are 6 representations and nine modes. The problem I have is: When I run the input file <a href="http://UO2.ph.in" target="_blank">UO2.ph.in</a>,<span style="color:rgb(255,0,0)"> <b>the scf calculation</b></span> for the the second representation of the second mode for q (-0.1666667 0.1666667 -0.1666667)<b style="color:rgb(255,0,0)"> is not converge.</b><br>
<br>Notes:<br>1- My runs assume UO2 is metallic, in fact UO2 is insulator with band gap of 2eV.( However, when I do the calculations using the VASP code I got very good result only by including the polarization effects) <br>
2- In order to account for the band gap, one should implement the Hubbard term (LDA/GGA+U)<br>3- I tried different occupations (smearing, tetrahedra)<br>4- I tried different starting_magnetization= 0.5, 1.0<br>5- I treid different mixing_betas (0.7, 0.35 )<br>
5- the lattice parameter a= 10.285, is based on optimizing the structure and including spin-polarization effects.<br>
<br><br>Any adivce to overcome this problem is highly welcomed.<br><br>Kindest Regards,<br>______________________________<br>aIYAD I. AL-QASIR, PhD<br>Research Associate <br><br>Department of Nuclear Engineering<br>North Carolina State University<br>
Campus Box 7909<br>2500 Stinson Dr.<br>Raleigh, NC 27695-7909<span class="HOEnZb"><font color="#888888"><br>
</font></span></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><br>-- <br>_______________________________<br>IYAD I. AL-QASIR, PhD<br>Research Associate <br><br>Department of Nuclear Engineering<br>North Carolina State University<br>
Campus Box 7909<br>2500 Stinson Dr.<br>
Raleigh, NC 27695-7909<br>
</font></span><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br><div dir="ltr">==========================================<br>Seyed Mojtaba Rezaei Sani<br>Computational Materials Science Research Lab<br>Physics Department, Isfahan University of Technology<br>
84156-83111 Isfahan, Iran<br>Tel lab: +98 311 391 3731 <br>Group page: <a href="http://cmsgroup.iut.ac.ir/" target="_blank">http://cmsgroup.iut.ac.ir/</a><br><a href="mailto:s.rezaeisani@ph.iut.ac.ir" target="_blank">s.rezaeisani@ph.iut.ac.ir</a><br>
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