<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1106" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Dear Paula,</FONT></DIV>
<DIV><FONT face=Arial size=2>Many thanks for the suggestion.</FONT></DIV>
<DIV><FONT face=Arial size=2>Does this mean that I should do total energy
derivations for (i) a structure containing only Si (ii) a structure containing
only C and (iii) subtract from the total energy for SiC. </FONT></DIV>
<DIV><FONT face=Arial size=2>Or are these values available within the
derivations for SiC itself?</FONT></DIV>
<DIV><FONT face=Arial size=2>Thank you,</FONT></DIV>
<DIV><FONT face=Arial size=2>Chandrika</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=pralonso@cnea.gov.ar href="mailto:pralonso@cnea.gov.ar">Paula R.
Alonso</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=wien@zeus.theochem.tuwien.ac.at
href="mailto:wien@zeus.theochem.tuwien.ac.at">A Mailing list for WIEN2k
users</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, September 26, 2005 9:07
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [Wien] total energy value
too high</DIV>
<DIV><BR></DIV>
<DIV>
<DIV><FONT face=Arial size=2>Free energy </FONT><FONT face=Arial
size=2>of formation is referred to the pure structures. You have to substrat
from the total energy of the compound the total energy of the pure elements in
the same structure, weighted by atomic fraction.</FONT></DIV>
<DIV><FONT face=Arial size=2>You obtain total energy in Ry/cell. You must
first convert it to Ry/at. T</FONT><FONT face=Arial size=2>hen, 1Ry/at
</FONT><FONT face=Arial size=2>= 13.13 x 10^5 Joule/
mole .</FONT></DIV>
<DIV><FONT face=Arial size=2>Paula Alonso</FONT></DIV>
<DIV> </DIV>
<DIV>Departamento de Materiales – Centro Atómico Constituyentes</DIV>
<DIV>Comisión Nacional de Energía Atómica</DIV>
<DIV>Avda Gral Paz 1499, San Martín, Buenos Aires, CP B1650KNA</DIV>
<DIV> Argentina.</DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message -----
</DIV></BLOCKQUOTE></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=rcais@cal3.vsnl.net.in
href="mailto:rcais@cal3.vsnl.net.in">Chandrika</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=Wien@zeus.theochem.tuwien.ac.at
href="mailto:Wien@zeus.theochem.tuwien.ac.at">Wien@zeus.theochem.tuwien.ac.at</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, September 26, 2005 3:40
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [Wien] total energy value too
high</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Hello Wien Users,</FONT></DIV>
<DIV><FONT face=Arial size=2>I am trying to derive the total energy of SiC
in order to later derive its standard free energy of formation. With all
three options in Wien2k 05 (13, 14 and 5) I get values near -656 Ry.
</FONT><FONT face=Arial size=2>(i) I presumed that the value derived by Wien
is Ry <EM>per unit cell</EM>. Is that correct?</FONT></DIV>
<DIV><FONT face=Arial size=2>(i) Therefore to convert to kcal/mole, I
used 1Ry = 13.13 x 10^5 Joule/ mole . Is this okay?</FONT></DIV>
<DIV><FONT face=Arial size=2>(iii) The derived value of total energy of SiC
is then -861300 KJoule/mole. This is several orders of magnitude higher
than the free energy of formation of SiC which is -72.2
KJoule/mole.</FONT></DIV>
<DIV><FONT face=Arial size=2>Could anyone suggest where I have gone
wrong?</FONT></DIV>
<DIV><FONT face=Arial size=2>I would particularly like to know about the
conversion units.</FONT></DIV>
<DIV><FONT face=Arial size=2>Thanks in advance.</FONT></DIV>
<DIV><FONT face=Arial size=2>Chandrika</FONT></DIV>
<DIV><FONT face=Arial
size=2>-----------------------------------------------------------------------------------------<BR>Dr
(Ms) Chandrika Varadachari<BR>Raman Centre for Applied and Interdisciplinary
Sciences<BR>16A Jheel Road<BR>Calcutta 700075<BR>India<BR>Tel :
91-33-24830029<BR>Fax : 91-33-24180610<BR>web : <A
href="http://www.rcais.org.in">www.rcais.org.in</A></FONT></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>Wien mailing
list<BR>Wien@zeus.theochem.tuwien.ac.at<BR>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<BR>
<P>
<HR>
<P></P>Internal Virus Database is out-of-date.<BR>Checked by AVG
Anti-Virus.<BR>Version: 7.0.296 / Virus Database: 267.11.3 - Release Date:
19/09/05<BR></BLOCKQUOTE>
<P>
<HR>
<P></P>_______________________________________________<BR>Wien mailing
list<BR>Wien@zeus.theochem.tuwien.ac.at<BR>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien<BR></BLOCKQUOTE></BODY></HTML>