[Pw_forum] problem with ibrav=13 again

[Tone Kokalj]

On Wed, 2009-02-04 at 11:23 +0000, hania djani-ait aissa wrote:
> Dear all,
> thank you for your quick reply, the structure should look as stacked
> multilayers of Bi2O2 slabs and perovskites ones along a-axis. i will
> use the latest version of Xcrysden and check if the problem  still
> persist. here my total input file:

Based on your input, I just checked that the new xcrysden version uses
the lattice for ibrav=13 as specified in the pwscf documentation for
ibrav13, i.e.:

celldm(1)=a, celldm(2)=b/a, celldm(3)=c/a, celldm(4)=cos(ab)

   v1 = (  a/2,         0,                -c/2),
   v2 = (b*cos(gamma), b*sin(gamma), 0),
   v3 = (  a/2,         0,                  c/2),

where gamma is the angle between axis a and b

There is indeed some problem in your structure: some Bi and O atoms are
too close (only 1.1 Angs). Please check the coordinates of atoms 5, 6, 7
and 8 (in particular the two oxygens).

Regards, Tone
-- 
Anton Kokalj
J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia 
(tel: +386-1-477-3523 // fax:+386-1-477-3822)

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