How about trying the spacegroup code in Exciting or ELK package?
At 2012-05-04 21:31:48,"Peng Chen" <pchen at ion.chem.utk.edu> wrote: Dear All, Is there any tools (free) to convert a conventional unit cell to a primitive cell? Recently, I tried to convert atom positions from a face centered orthorhombic unit cell (space group cmca, basis vectors: a,b,c) to its primitive cell. I used basis vectors: 1/2(a,0,c), 1/2(a,b,0),1/2(0,b,c). But it looks they are not the correct ones because the chemical formula in this unit cell is not the same as that in conventional unit cell. -- Best Regards. Peng -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120504/204bfc82/attachment.htm