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<DIV><FONT size=2 face=Arial>It's up to what kind of system you are studying.
For a system with orthorhombic, monoclinic</FONT></DIV>
<DIV><FONT size=2 face=Arial>or triclinic structure, my experience told me that
vc-relax is much faster than the "static"</FONT></DIV>
<DIV><FONT size=2 face=Arial>method because in those cases you need to do a
series of calculations for each parameter,</FONT></DIV>
<DIV><FONT size=2 face=Arial>b/a, c/a as well as volume for example of
orthorhombic system.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>huiqun zhou</FONT></DIV>
<DIV><FONT size=2 face=Arial>@earth sciences, nanjing university,
china</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=jiachen@princeton.edu href="mailto:jiachen@princeton.edu">jia
chen</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=pw_forum@pwscf.org
href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, August 25, 2010 2:51
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [Pw_forum] ambiguous results
with vc-relax</DIV>
<DIV><BR></DIV>sorry for interrupting you guys, I didn't follow the whole post
before. Pressure calculations need very high ecutoff. And,according to my
experience, vc-relax is supposed to be slow. So, I usually avoid vc-relax if
possible... Last but not least, I am a student, maybe very wrong. Have a good
day.<BR clear=all><BR>-- <BR>Jia Chen<BR><BR>Dept of Chemistry<BR>Princeton
University<BR>Princeton, NJ 08544<BR>
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