one possibility cound be to use ibrav=0 and then provide the bravais lattice vector as required by your cell via the CELL_PARAMETERS card... Hope this helps stefano
hania djani-ait aissa wrote: > 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 > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > ------------------------------------------------------------------------ > Vous voulez savoir ce que vous pouvez faire avec le nouveau Windows > Live ? Lancez-vous ! > <http://www.microsoft.com/windows/windowslive/default.aspx> > ------------------------------------------------------------------------ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
