Dear GAO Zhe and QE users...Thanks alot for your quick reply.<br><br>I have calculated the phonon DOS value and by fqha.x utility which is given in PH/fqha.x. I have calculated the free energy F(T) at different temperature.<br>
The
normalised phonon 3*N=6.00011 getting which is right.(i am taking 2
atoms in unit cell as FCC in zincblende structure). the Desprsion
relation of frequency and PHDOS graph was also seems right.<br>
<br><br> But realy i want to calculate Specific heat (C_v), Entropy. so
for that i was tried for QHA package which was given in QE, but it is
not giving the accurate value and very less value i was getting in order
of 10^-7 of Cv.<br> Here i an attaching the PHDOS.out file please see it.<br>
<br>Sir please help me in this regard how can i calculate the Cv value
and other thermodynamical parameters. <br><br>I am heartily appreciated any help regarding this problem.<br><div class="yj6qo ajU"><div id=":271" class="ajR" tabindex="0"><img class="ajT" src="images/cleardot.gif"></div>
</div><br><br><div class="gmail_quote">2012/2/9 GAO Zhe <span dir="ltr"><<a href="mailto:flux_ray12@163.com">flux_ray12@163.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="line-height:1.7;font-size:14px;font-family:arial">You can obtain thermodynamics properties at finite temperature by calculating phonon (ph.x) and treating phonon through QHA method. If temperature was high, you may need an-harmonic calculation by d3.x<span class="HOEnZb"><font color="#888888"><br>
<br><div>--<br>GAO Zhe<br>CMC Lab, Materials Science & Engineering Department,<br>Seoul National University, South Korea<br>
</div></font></span><div><div class="h5"><div></div><br>At 2012-02-09 22:49:27,"bramha pandey" <<a href="mailto:pandey.bramha@gmail.com" target="_blank">pandey.bramha@gmail.com</a>> wrote:<br> <blockquote style="PADDING-LEFT:1ex;MARGIN:0px 0px 0px 0.8ex;BORDER-LEFT:#ccc 1px solid">
<br clear="all">Dear QE users...<br><br>i want to know how we can introduce the temperature in our equilibrium system(i.e after running scf with proper setting of lattice parameter, ecut and k point, we get ground state total energy(T=0) in scf run).<br>
<br>As i read somewhere that SCF will gives the minimum total energy at T=0, because in DFT there is no term of temperature.<br>May be i am wrong but can we introduce temperature by changing the any parameter in input file of pw.x. Actualy i want to generate the phonon by the thermal excitation in my input file by increasing the temperature of my system or any other means by which i can generate phonon for thermo-dynamical property calculation of the system.<br>
<br>Any type of help will be appreciable . <br><br><br>-- <br>Thanks and Regards<br>Bramha Prasad Pandey<br>Assistant Professor (Electronics and Communication Engg)<br>GLA Group of Institutions, Mathura.<br>Ph. No. 08954143009<br>
email id <a href="mailto:pandey.bramha@gmail.com" target="_blank">pandey.bramha@gmail.com</a><br> <a href="mailto:bpglaitm@yahoo.co.in" target="_blank">bpglaitm@yahoo.co.in</a><br>
</blockquote></div></div></div><br><br><span title="neteasefooter"><span></span></span></blockquote></div><br><br clear="all"><br>-- <br>Thanks and Regards<br>Bramha Prasad Pandey<br>Assistant Professor (Electronics and Communication Engg)<br>
GLA Group of Institutions, Mathura.<br>Ph. No. 08954143009<br>email id <a href="mailto:pandey.bramha@gmail.com">pandey.bramha@gmail.com</a><br> <a href="mailto:bpglaitm@yahoo.co.in">bpglaitm@yahoo.co.in</a><br>