The ABINIT Users Mailing List ( CLOSED )

[Xavier Gonze <xavier.gonze@uclouvain.be>]

On 26 Jun 2009, at 12:04, Marino Vetuschi Zuccolini wrote:

> Hello to all,
>
> playing with a rhombohedral structure (carbonate minerals as  
> calcite, R-3c, class 167 H-M) with abinit, I found that the  
> fractional coordinates matrix here in the following it is not  
> recognized as a member to that class but to class 148 H-M. it is a  
> problem due to an insufficient number of digits or it is my fault?   
> Other software recognize unambiguously the structure as R-3c.

You should have at least

C 0.25 0.25 0.25
C 0.75 0.75 0.75

and the O coordinates should be corrected also ...

X.

> Many thanks for your help
>
>
> Fe1      0.000000000  -0.000000000   0.000000000
> Fe2      0.500000000   0.500000000   0.500000000
> C        0.249919131   0.249919131   0.249919131
> C        0.750080869   0.750080869   0.750080869
> O       -0.019563280   0.519848977   0.249446873
> O        0.519848977   0.249446873  -0.019563280
> O        0.249446873  -0.019563280   0.519848977
> O        0.019563280   0.480151023   0.750553127
> O        0.480151023   0.750553127   0.019563280
> O        0.750553127   0.019563280   0.480151023
>
>
>
> *******************************************************
> Marino Vetuschi Zuccolini
> zucco@dipteris.unige.it
> Researcher / Geochemist
> Laboratory of Geochemistry
>
> DIPartimento per lo studio della TErra e delle sue RISorse -  
> Università  di Genova
> Tel. ++39 010 3538136 Fax. ++39 010 352169
> Corso Europa 26, 16132 - Genova - Italy