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<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>Dear
Yundi, </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>What I
follow is </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>1. do
volume or c/a, b/a relaxation depending on your structure</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>2. Use
the optimized lattice parameters to do min_lapw </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>3. Use
the optimized lattice parameters and atomic positions to define the supercell in
Phonon software </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>4.
import the d45 file from phonon to wien2k</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>5. run
phonon.job in wien2k</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>6. get
the force file and export it to phonon </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>7. get
the phonon dispersion</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT
face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>you can
use -fc 1.0 in min_lapw as well as in phonon. you can then try -fc 0.50 and then
so on </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT
face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT face=Arial>SG
</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=690504711-26092011><FONT
face=Arial></FONT></SPAN> </DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B> wien-bounces@zeus.theochem.tuwien.ac.at
[mailto:wien-bounces@zeus.theochem.tuwien.ac.at] <B>On Behalf Of </B>Yundi
Quan<BR><B>Sent:</B> Monday, September 26, 2011 3:41 PM<BR><B>To:</B> A Mailing
list for WIEN2k users<BR><B>Subject:</B> [Wien] phonon
calculation<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>In order to get the correct input structure for phonon calculation, I need
to first find the structure with minimal force. How much force is small enough?
Is 1.0 mRy/bohr small enough? (I only want to calculate the phonon at gamma
point to see whether the system is stable or not at gamma point)</DIV>
<DIV>Should I first carry out internal structure minimization or crystal
structure minimization? </DIV>
<DIV><BR></DIV>
<DIV>
<DIV><BR></DIV>
<DIV><BR></DIV>
<DIV>Yundi</DIV></DIV></BODY></HTML>