[Pw_forum] help... taking care of all symmetry operations (fwd)

[Stefano Baroni]

Please, take a glance at the pwscf users' manual, as suggested by Paolo 
Giannozzi. I did the same before replying to you, and I can assure that 
everything is explained in full detailed. Thank you for using PWscf and 
for reporting your problems to this mailing list. Regards, Stefano 
Baroni

On Mar 9, 2004, at 10:45 AM, Mousumi Upadhyay wrote:

>
> THIS ONE WAS THE WHOLE MAIL I SENT. THEN, HOW SHOULD I GET RID OF THE
> PROBLEM I HAVE MENTIONED???
>
>
> ---------- Forwarded message ----------
> Date: Tue, 9 Mar 2004 12:19:03 +0530 (IST)
> From: Mousumi Upadhyay <mousumi at jncasr.ac.in>
> To: Eyvaz Isaev <eyvaz_isaev at yahoo.com>
> Cc: pw_forum at pwscf.org
> Subject: help... taking care of all symmetry operations
>
>
> Hi,
>
>          I want to know, how all the symmetry operations for my systems
> can be taken care of, through PWSCF?
>          I'm sending the following warning part,
> ""
>         input
>      warning: symmetry operation #  7 not allowed.   fractionary
> translation:
>        0.0000000  0.0000000  0.3333333  in crystal coordinates
>      warning: symmetry operation #  8 not allowed.   fractionary
> translation:
>        0.0000000  0.0000000 -0.3333333  in crystal coordinates
>      warning: symmetry operation # 11 not allowed.   fractionary
> translation:
>        0.0000000  0.0000000 -0.3333333  in crystal coordinates
>      warning: symmetry operation # 12 not allowed.   fractionary
> translation:
>        0.0000000  0.0000000  0.3333333  in crystal coordinates""
>
>
>                 But in our system, in a unit cell, three atoms are in
> three different levels, 0, 1/3 & 2/3. So, this must be taken care of
> to get relaxed reduced co-ordinates.
>
>                 For example, starting at some lattice constant value,
> with reduced co-ordinate,
>         2.16500000000E-01  0.0000000000E+00 -1.8503717077E-17    1
>        -2.16500000000E-01 -2.16500000000E-01  3.3333333333E-01    1
>         0.0000000000E+00  2.16500000000E-01  6.6666666667E-01    1
>
> final reduced co-ordinates, we got as,
>         0.208561119   0.000000000   0.000000000  1
>        -0.206588002  -0.204614884   0.336091984  1
>        -0.001973118   0.204614884   0.663908016  1
>
> The values, 0.2085, 0.2065, 0.2046 are all expected to be same atleast
> upto 4th deecimal places. I believe this discripency is because, all
> symmetry operations are not taken care of. So, how can we get rid of 
> that
> in PWSCF??? By which input parameter?
>
>        Best regards,   Mousumi.
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>
---
Stefano Baroni    ---  SISSA  &  DEMOCRITOS National Simulation Center
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