You are right. The spin state is different in two cases. Applying U after a scf calculation seems to tend to reduce the magnetic moments.<br><br><br><br><br><br><br><br><div class="gmail_quote">On Thu, Feb 16, 2012 at 3:44 PM, Laurence Marks <span dir="ltr"><<a href="mailto:L-marks@northwestern.edu">L-marks@northwestern.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left:1px solid rgb(204,204,204);margin:0pt 0pt 0pt 0.8ex;padding-left:1ex">If all other things are the same, the lowest energy is correct<br>
(variational principle). Probably the spin state is different in the<br>
two cases.<br>
<br>
But...please ensure that you really have both converged. Assuming that<br>
you have a recent version, do a "grep -e :MV case.scf" (with case<br>
replaced as appropriate). The % value should be small for true<br>
convergence; if it is not you do not have real convergence<br>
(technically it is called a "trap").<br>
<br>
2012/2/16 Yundi Quan <<a href="mailto:quanyundi@gmail.com">quanyundi@gmail.com</a>>:<br>
<div><div></div><div class="h5">> Dear Sir/Madam,<br>
> When using LSDA+U, it is recommended to first do an LSDA caculation and then<br>
> turn on U. I first did an LSDA calculation to convergence. Then, I turned on<br>
> U. I also did a calculation by turning on U from the very beginning. I<br>
> compared the two results, and found that the later is lower in energy. Which<br>
> one is correct?<br>
><br>
><br>
><br>
><br>
><br>
</div></div>> _______________________________________________<br>
> Wien mailing list<br>
> <a href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br>
> <a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
><br>
<font color="#888888"><br>
<br>
<br>
--<br>
Professor Laurence Marks<br>
Department of Materials Science and Engineering<br>
Northwestern University<br>
<a href="http://www.numis.northwestern.edu" target="_blank">www.numis.northwestern.edu</a> <a href="tel:1-847-491-3996" value="+18474913996">1-847-491-3996</a><br>
"Research is to see what everybody else has seen, and to think what<br>
nobody else has thought"<br>
Albert Szent-Gyorgi<br>
_______________________________________________<br>
Wien mailing list<br>
<a href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</a><br>
<a href="http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien" target="_blank">http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien</a><br>
</font></blockquote></div><br>