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

[Mousumi Upadhyay]

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.