<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt">Dear Sonu,<br><br>Of course, there is no cutoff energy in phonon input file. But the second order derivatives to define phonons are related to the charge density and its first order derivative. So, phonons are dependent on the cutoff energy. In its turn, the cutoff energy is connected to a Pseudo-type used. <br><br>Yes, I meant tr2_ph parameter. <br><br>Bests,<br>Eyvaz.<br><div> -------------------------------------------------------------------<br></div>Prof. Eyvaz Isaev, <br>Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden <br>Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, <br>isaev@ifm.liu.se, eyvaz_isaev@yahoo.com<div><br></div><div style="font-family: times new roman,new york,times,serif;
font-size: 12pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> sonu kumar <1009ukumar@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> pw_forum@pwscf.org<br><b><span style="font-weight: bold;">Sent:</span></b> Sat, July 31, 2010 7:41:07 AM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: [Pw_forum] Fourier interpolation<br></font><br>
<span class="Apple-style-span" style="font-family: arial,sans-serif; font-size: 12.5px; border-collapse: collapse;"><div><b><span class="Apple-style-span" style="font-size: small;">Dear Prof. </span></b><b><span class="Apple-style-span" style="font-size: small;">Eyvaz Isaev and QE users,</span></b></div>
<div><b><span class="Apple-style-span" style="font-size: small;"><br></span></b></div><b><span class="Apple-style-span" style="font-size: small;">> Play around cutoff energy and the threshold parameter for phonons.<br>
<br></span></b></span><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>where is the cutoff energy parameter related to phonon calculations?</b></span></div><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b><br>
</b></span></div><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>i couldn't find it in the manual for ph.x. Only "tr2_ph" theshold </b></span><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>parameter is </b></span></div>
<div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>there in addition to "eth_rps" and "eth_ns" </b></span><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>parameters for Raman calculations.</b></span></div>
<div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b><br></b></span></div><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>i am sorry if am wrong.</b></span></div>
<div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>Thank you very much.</b></span></div><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b><br>
</b></span></div><div><span class="Apple-style-span" style="font-family: arial,sans-serif; border-collapse: collapse;"><b>With Kind Regards,</b></span></div><div><div><b>Sonu Kumar</b></div><div><b>Phd Student<br>Physics Department<br>
IIT Delhi<br></b><br>
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