[Pw_forum] relaxating only z coordinate

[ambavale sagar]

Dear Manoj

i.e now in your input file the atomic position card will look like:

ATOMIC POSITIONS
Si     0        0        0    0    0    1
Si    0.5    0.5    0.5    0    0    1
Si    0.7    0.7    0.7    1    0    0

This atomic position card allow you to displace  first two atoms in z direction while the third Si in x direction. 


Regards
Sagar Ambavale
The M. S. University of Baroda
India
===============================


Message: 8
Date: Wed, 23 Sep 2009 17:50:22 -0400 (EDT)
From: Manoj Srivastava <manoj at phys.ufl.edu>
Subject: [Pw_forum] relaxating only z coordinate?
To: PWSCF Forum <pw_forum at pwscf.org>
Message-ID:
    <Pine.GSO.4.21.0909231745570.15412-100000 at neptune.phys.ufl.edu>
Content-Type: TEXT/PLAIN; charset=US-ASCII

Dear PWSCF users, 
This might have been answered previously, but I was unable to find
it. How can one relax only z coordinate of atoms inside unit cell using
PW? In other words how can I constrain x and y coordinates of atoms during
relaxation?


Regards, 
Manoj Srivastava
University of Florida 
Gainesville, FL 



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

Message: 9
Date: Thu, 24 Sep 2009 06:29:11 +0800
From: lan haiping <lanhaiping at gmail.com>
Subject: Re: [Pw_forum] relaxating only z coordinate?
To: PWSCF Forum <pw_forum at pwscf.org>
Message-ID:
    <c92002fa0909231529v5070ed6yd2263af504c2dd61 at mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"

Hi, Please check INPUT_PW document,  you will find below description:
if_pos(1), if_pos(2), if_pos(3) INTEGER  *Default:* 1

component i of the force for this atom is multiplied by if_pos(i),
which must be either 0 or 1.  Used to keep selected atoms and/or
selected components fixed in meta-dynamics, neb, smd, MD dynamics or
structural optimization run.

If you want to fix some atom or some direction , just set if_pos(i) =0 .

Regards,

Hai-Ping


      From cricket scores to your friends. Try the Yahoo! India Homepage! http://in.yahoo.com/trynew
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20090924/cd3a1dde/attachment.html>