<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;"><br>Dear Sandro,<br><br>Thanks very much,<br>May be I should search for another method to compute the diffusion coefficient.<br><br><br>Best regards.<br><br>****************************<br>
Bertrand SITAMTZE YOUMBI<br>
Laboratory of Material Sciences<br>
Department of Physics<br>
University of Yaounde I-Cameroon<br>
************************************<br><br>--- En date de : <b>Sam 1.5.10, Sandro Scandolo <i><scandolo@ictp.it></i></b> a écrit :<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>De: Sandro Scandolo <scandolo@ictp.it><br>Objet: Re: [Pw_forum] About the mean square displacement in CP output<br>À: "PWSCF Forum" <pw_forum@pwscf.org><br>Date: Samedi 1 mai 2010, 12h33<br><br><div id="yiv1371329877">
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Dear Bernard,<br>
<br>
if it converges to a finite value, your system is a solid (a crystal or
a glass), not a fluid, so it makes no sense to compute the diffusion
coefficient with MD, as the time scale for diffusion in solids are
dictated by defect diffusion, which takes place on a much longer time
scale than a MD simulation. <br>
<br>
NB: The MSD is also printed out (together with the temperature of each
species) in the standard output of cp.x, every iprint. <br>
<br>
Regards<br>
Sandro <br>
<br>
On 30/04/2010 17:28, Bertrand SITAMTZE wrote:
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<td style="font: inherit;" valign="top">Dear Sandro,<br>
<br>
Thanks very much for giving tangible responses to my questions.<br>
My aim was to compute the diffusion coefficient using the linear
dependence of the MDS(t). Now that it converge to a finite value, how
should I proceed?<br>
<br>
Your help is of great interest for me.<br>
Thanks once again<br>
<br>
****************************<br>
Bertrand SITAMTZE YOUMBI<br>
Laboratory of Material Sciences<br>
Department of Physics<br>
University of Yaounde I-Cameroon<br>
************************************<br>
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