<div style="line-height:1.7;color:#000000;font-size:14px;font-family:arial">Prof. Giannozzi:<br>Thank you very much for your kindly reply. I think this is my problem to understand Fvib.<br>I have also checked Axel van de Walle's Ph.D thesis, and found that free energy should be Fvib+Fconf-TSvib-TSconf. In 0GPa pressure case, Fconf should equal to total energy. Therefore I cannot obtain the right Free Energy vs Volume curve as a result of using Fvib alone.<br><br><div>--<br>GAO Zhe<br>CMC Lab, MSE, SNU, Seoul, S.Korea<br>        
</div><div id="divNeteaseMailCard"></div><br><pre><br>At&nbsp;2011-08-30&nbsp;03:42:31,"Paolo&nbsp;Giannozzi"&nbsp;&lt;giannozz@democritos.it&gt;&nbsp;wrote:
&gt;
&gt;On&nbsp;Aug&nbsp;22,&nbsp;2011,&nbsp;at&nbsp;4:36&nbsp;,&nbsp;GAO&nbsp;Zhe&nbsp;wrote:
&gt;
&gt;&gt;&nbsp;However,&nbsp;the&nbsp;free&nbsp;energy&nbsp;kept&nbsp;decreasing&nbsp;as&nbsp;a&nbsp;monotone&nbsp;decreasing
&gt;&gt;&nbsp;function&nbsp;of&nbsp;lattice&nbsp;parameter
&gt;
&gt;you&nbsp;mean:&nbsp;the&nbsp;"vibrational&nbsp;free&nbsp;energy"&nbsp;alone,&nbsp;or&nbsp;"the&nbsp;sum&nbsp;of&nbsp;the
&gt;energy&nbsp;and&nbsp;of&nbsp;the&nbsp;vibrational&nbsp;free&nbsp;energy"?&nbsp;the&nbsp;vibrational&nbsp;free
&gt;energy&nbsp;should&nbsp;be&nbsp;a&nbsp;small&nbsp;correction&nbsp;to&nbsp;the&nbsp;total&nbsp;energy.
&gt;
&gt;P.
&gt;---
&gt;Paolo&nbsp;Giannozzi,&nbsp;Dept&nbsp;of&nbsp;Chemistry&amp;Physics&amp;Environment,
&gt;Univ.&nbsp;Udine,&nbsp;via&nbsp;delle&nbsp;Scienze&nbsp;208,&nbsp;33100&nbsp;Udine,&nbsp;Italy
&gt;Phone&nbsp;+39-0432-558216,&nbsp;fax&nbsp;+39-0432-558222
&gt;
&gt;
&gt;
&gt;
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