<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:10pt">but is it possible to calculate phonon after doing gamma point relaxation?<br><div> </div>-- <br>Rudra<br>Have a Nice Time<br><span><a target="_blank" href="http://www.bose.res.in/%7Erudra">http://www.bose.res.in/~rudra</a></span><br>Please, if possible, don't send me MS Word or PowerPoint attachments <br><span>Why?See: <a target="_blank" href="http://www.gnu.org/philosophy/no-word-attachments.html">http://www.gnu.org/philosophy/no-word-attachments.html</a></span><div style="font-family: times new roman,new york,times,serif; font-size: 10pt;"><br><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">----- Original Message ----<br>From: Paolo Giannozzi <giannozz@nest.sns.it><br>To: PWSCF Forum <pw_forum@pwscf.org><br>Sent: Monday, 7 January,
2008 2:05:21 PM<br>Subject: Re: [Pw_forum] time requirement<br><br>On Jan 7, 2008, at 6:38 , Rudra Banerjee wrote:<br><br>> my machine(desktop,linux) is 3 GB ram, but yet it is using more space<br>> (SWAP) and giving only 2-3 iteration per day.<br>> is my input somewhat inefficient? pl. let me suggest any <br>> improvement if possible<br><br>assuming that you cannot reduce the size cell and the cutoff:<br>- do not calculate stress if you do not need to: it is expensive<br>- conv_thr = 1.0d-10 is quite high, 1.0d-8 should be enough<br>- is your system an isolated system? then use<br>K_POINTS gamma :<br> it will use k=0 only (which is all you need for an isolated system)<br> and exploit various tricks to reduce memory usage<br>- setting option "diago_david_ndim" to the minimum (2) and
"mixing_ndim"<br> to a smaller value (4) reduces memory usage, but may increase CPU <br>time<br>- using diagonalization='cg' will also reduce memory usage, but it will<br> increase CPU time by a sizable amount<br><br>P.<br>---<br>Paolo Giannozzi, Dept of Physics, University of Udine<br>via delle Scienze 208, 33100 Udine, Italy<br>Phone +39-0432-558216, fax +39-0432-558222<br><br><br><br>_______________________________________________<br>Pw_forum mailing list<br><a ymailto="mailto:Pw_forum@pwscf.org" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br><a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br></div><br></div></div><br>
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