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<DIV><FONT face=Verdana color=#000080 size=2>Hi:</FONT></DIV>
<DIV><FONT color=#000080>A slab is used in my simulation.</FONT></DIV>
<DIV><FONT color=#000080>Thanks!</FONT></DIV>
<DIV><FONT face=Verdana color=#000080 size=2></FONT> </DIV>
<DIV><FONT face=Verdana color=#000080 size=2></FONT> </DIV>
<DIV><FONT face=Verdana color=#c0c0c0 size=2>2009-06-30 </FONT></DIV><FONT
face=Verdana color=#000080 size=2>
<HR style="WIDTH: 100px" align=left color=#b5c4df SIZE=1>
</FONT>
<DIV><FONT face=Verdana color=#c0c0c0 size=2><SPAN>shypirate</SPAN>
</FONT></DIV>
<HR color=#b5c4df SIZE=1>
<DIV><FONT face=Verdana size=2>
<DIV></DIV><STRONG></STRONG>Hi,</DIV>
<DIV>
<DIV></DIV>
<DIV>I have a question about your setup for simulation .</DIV>
<DIV>Is it a slab or bulk ?</DIV>
<DIV>If it is a bulk, you should make sure what your purpose is for applying a</DIV>
<DIV>saw-tooth electric field.</DIV>
<DIV></DIV>
<DIV>Regards,</DIV>
<DIV></DIV>
<DIV>On Tue, Jun 30, 2009 at 10:05 AM, shypirate <shypirate@gmail.com> wrote:</DIV>
<DIV></DIV>
<DIV>> Dear all:</DIV>
<DIV>> I have used PWscf to do atomic position relaxition under finite electric</DIV>
<DIV>> field. The electric field is applied by adding a saw-like potential to bare</DIV>
<DIV>> ionic potential. The total force calculated seems not to be convergent. And</DIV>
<DIV>> there are two questions unclear for me:</DIV>
<DIV>> 1. In atomic position relaxition, does the force from external electric</DIV>
<DIV>> field contribute to total force?</DIV>
<DIV>> 2. Will all the atoms move along the direction of external electric field</DIV>
<DIV>> as a whole? If that happens, the total energy and total force can not get</DIV>
<DIV>> convergence.</DIV>
<DIV>></DIV>
<DIV>> Thanks for your warmly help!</DIV>
<DIV>></DIV>
<DIV>> Y.P.Wang</DIV>
<DIV>></DIV>
<DIV>> 2009-06-30</DIV>
<DIV>> ------------------------------</DIV>
<DIV>> shypirate</DIV>
<DIV>></DIV>
<DIV>> _______________________________________________</DIV>
<DIV>> Pw_forum mailing list</DIV>
<DIV>> Pw_forum@pwscf.org</DIV>
<DIV>> http://www.democritos.it/mailman/listinfo/pw_forum</DIV>
<DIV>></DIV>
<DIV>></DIV>
<DIV></DIV>
<DIV></DIV>
<DIV>-- </DIV>
<DIV>Hai-Ping Lan</DIV>
<DIV>Department of Electronics ,</DIV>
<DIV>Peking University , Bejing, 100871</DIV>
<DIV>lanhaiping@gmail.com, hplan@pku.edu.cn</DIV></FONT></DIV></BODY></HTML>