[Pw_forum] optimize the amorphour structure

[Jean-Yves Raty]

Hello,

 

To my opinion, if you did not perform a constant-pressure quench of your
liquid phase, it is necessary to relax the cell parameters of your ‘frozen
liquid’ and the ionic positions. This is because usually the amorphous does
not have the same density as the liquid. Now as you know, there is no
guarantee the your frozen liquid will actually give you a reasonable model
for the amorphous state, as the time scale for your quench is several orders
of magnitude too short in comparison with a ‘real quench’.

 

Good luck

 

JY

 

----------------------------------------------------------------------------
-------------------

Jean-Yves Raty

FNRS - Université de Liège               Tel   +32 4 3663747

Condensed Matter Physics B5         Fax   +32 4 3662990

4000 Sart-Tilman                              Belgium

----------------------------------------------------------------------------
-------------------

 

From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf
Of li niu
Sent: mercredi 25 avril 2007 0:24
To: pwscf
Subject: [Pw_forum] optimize the amorphour structure

 

Dear all,


I want to use a given amorphous network that generated by liquid quench 

method using Car-Parrinello molecular dynamics to investigate its 

vibrational properties.I know each calculation should be performed at 

the respective optimized lattice constant.
Need I optimize this structure ? If the answer is yes, I use the relax,
vc-relax or others?

 

Thanks!

 

Niu Liu

  

  _____  

 <http://cn.mail.yahoo.com> 抢注雅虎免费邮箱3.5G容量，20M附件！ 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20070425/f2d9964e/attachment.html>