thanks for reply,
actually, the problem is that the data collected by neutron diffraction gives a
non-standard A2/m structure with a=8.37Angstrom, b=3.85A. c=16.44 and Beta
>90?=102.334?. for pwscf recognize my structure i had to transforme A2/m to
C2/m by swapping a and c axis and swapping x and z coordinates. however pwscf
gives for ibrav=13 celldm(4)=cos(gamma) and my angle is Beta between ac.
hania> From: tone.kokalj at ijs.si> To: pw_forum at pwscf.org> Date: Wed, 4 Feb
2009 13:26:02 +0100> Subject: Re: [Pw_forum] problem with ibrav=13 again> > 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)> > Please, if possible, avoid sending me Word or
PowerPoint attachments.> See:
http://www.gnu.org/philosophy/no-word-attachments.html> >
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