[QE-users] Overlapping of different atoms

[Matthew Marcus]

The z-axis positions are not the same.  Also, (1/3,2/3,z) is equivalent to (-2/3,-1/3,z), not (2/3,1/3,z).  SG 164 (P-3m1), according to
http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-wp-list, doesn't have (x,y,z) equivalent to (-x,-y,z).  It's equivalent to (-x,-y,-z) and to (y,x,-z).

Sincerely,
     Matthew Marcus

On 12/4/2019 1:22 PM, Arles V. Gil Rebaza wrote:
> Dear Rodolfo, effectively atoms 2 and 3 have the same x and y positions. In crystal_sg units, atomic positions are from 0 to 1 (by periodicity). For example:  0.33333333 = 1 - 0.3333333 = 0.66666666
> So, (x,y) atomic position of the Mn and Bi are the same.
> 
> Best
> 
> Arles V. Gil Rebaza
> Instituto de Física La Plata - IFLP
> La Plata - Argentina.
> 
> El mié., 4 dic. 2019 a las 17:33, Rodolfo Tartaglia (<rodolfotartaglia.s at gmail.com <mailto:rodolfotartaglia.s at gmail.com>>) escribió:
> 
>     Dear QE users,
> 
>     I'm trying to do a scf calculation with the following parameters:
> 
>     %%%%%%%%%%%%%%%%%%
>     space_group = 164,
>          A = 4.63600,
>          B = 4.63600,
>          C = 7.6350,
>          cosAB = -0.5,
>          cosAC = 0,
>          cosBC = 0,
> 
>     ATOMIC_POSITIONS {crystal_sg}
>     Ca 1.000000 1.000000 1.000000
>     Mn 0.333333 0.666667 0.6192
>     Bi 0.666667 0.333333 0.753710
>     %%%%%%%%%%%%%%%%%%%
> 
>     and I got the error:
> 
>     %%%%%%%%%%%%%%%%
>     task #         0
>           from check_atoms : error #         1
>           atoms #   2 and #   3 overlap!
>     %%%%%%%%%%%%%%%%
> 
>     The problem is that the atomic positions are the ones that I got from a Rietveld refinement and when I tried to visualize with xCrysden there weren't errors. Could anyone help me?
> 
>     Thank you for your support.
> 
>     Best,
> 
>     Rodolfo
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> 
> 
> -- 
> Arles V.
> 
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