[CP2K:8838] Ab - initio MD of pure sodium

Aniruddha Dive anirudd... at gmail.com
Thu Mar 23 18:19:31 CET 2017


Thanks Juerg,

I shall try using Fermi smearing and diagonalization. Also I want to run a 
separate simulation for a sodium glass, in that case also do I need to use 
fermi smearing and diagonalization methods or is it the case only where 
pure metal is involved. I have a system where I have a pure sodium metal 
and glass containing sodium ions in contact. Should those be treated in the 
same way?

Thanks and Regards,
Aniruddha M Dive

On Thursday, March 23, 2017 at 2:31:56 AM UTC-7, jgh wrote:
>
> Hi 
>
> you are attempting a 0 K electronic structure calculation of 
> a metal. There is a good chance that you are simulating an 
> excited state. 
> Not using the Mermin functional (with Fermi smearing) for a metal 
> needs a lot of care and testing. I would suggest to use smearing 
> and diagonalization. It will need much more CPU time but is safe. 
>
> regards 
>
> Juerg 
> -------------------------------------------------------------- 
> Juerg Hutter                         Phone : ++41 44 635 4491 
> Institut für Chemie C                FAX   : ++41 44 635 6838 
> Universität Zürich                   E-mail: hut... at chem.uzh.ch 
> <javascript:> 
> Winterthurerstrasse 190 
> CH-8057 Zürich, Switzerland 
> --------------------------------------------------------------- 
>
> -----cp... at googlegroups.com <javascript:> wrote: -----To: cp2k <
> cp... at googlegroups.com <javascript:>> 
> From: Aniruddha Dive 
> Sent by: cp... at googlegroups.com <javascript:> 
> Date: 03/22/2017 06:54PM 
> Subject: [CP2K:8838] Ab - initio MD of pure sodium 
>
> Hi, 
>
> I am performing ab - initio MD for pure sodium at 300K which is room 
> temperature. After 1 ps run, I find that the crystal structure of the pure 
> sodium does not remain purely crystalline. I am not sure as to why this is 
> happening. There shall be certain vibrations of the sodium ions but the rdf 
> plot becomes more of an amorphous type after 1 ps of MD run. The sodium 
> uses semi core basis sets which has 9 valence electrons and hence I need to 
> use a higher value of cutoff (~ 950 Ry) which is equivalent to 12925 eV. Is 
> this high value of cutoff correct? Or am I just using too high a cutoff and 
> as a result of which the sodium atoms are behaving as liquid sodium? 
>
> I have attached my input file and trajectory files hereby. 
>
> Kindly let me know what am I doing wrong. 
>
> Thanks and Regards, 
> Aniruddha M Dive 
> PhD Student 
> Washington State University 
>
>
>
>
> -- 
>
> You received this message because you are subscribed to the Google Groups 
> "cp2k" group. 
>
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to cp2k+... at googlegroups.com <javascript:>. 
>
> To post to this group, send email to cp... at googlegroups.com <javascript:>. 
>
>
> Visit this group at https://groups.google.com/group/cp2k. 
>
> For more options, visit https://groups.google.com/d/optout. 
>
>
>
> [attachment "SODIUM_MD-pos-1.xyz" removed by Jürg Hutter/at/UZH] 
> [attachment "pure_sodium.inp" removed by Jürg Hutter/at/UZH] 
> [attachment "sodium.xyz" removed by Jürg Hutter/at/UZH] 
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20170323/479a9f9d/attachment.html>


More information about the CP2K-user mailing list