Hi Angga, Generally, yes if you do not use CELL_PARAMETERS card, which means the vectors are standard vectors generated from ibrav value you set.
However if you do use CELL_PARAMETERS card and set ibrav=0, ony A is used. In this case, A is simply a scaling factor. You can multiply A by 2, or multiply the vectors by 2. You also need to take care for atoms positions. For "crystal", atom position is scaled by both a/celldm(1) and cell vector while for "alat", it's scaled only by a/celldm(1). Regards, Yao On Sat, 8 Dec 2012 12:02:25 AM Angga Fauzi wrote: Dear all, I am trying a scf calculation in my system. My system is 2x2x2 ZnO supercell with 32 atoms. The lattice parameters of unit cell of ZnO are a=b=3.2495 angstrom and c=5.2069 angstrom. My question is should I multiply the lattice parameters by 2 when I perform a scf calculation for my system? Regards, Angga -- Yao Yao PhD. Candidate 3rd Generation Strand ARC Photovoltaics Centre of Excellence University of New South Wales Sydney, NSW Australia -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20121209/e8485f7c/attachment.html
