Dear Stefaan Cottenier Sir, Thank you very much for your reply. It resolves all of our doubts.
with best regards, Shamik Chakrabarti On Fri, Dec 10, 2010 at 3:43 PM, Stefaan Cottenier < Stefaan.Cottenier at ugent.be> wrote: > > We have done a calculation for a material >> having space group *Pnma.* The material has *4 in equivalent* atoms and >> total *20 atoms/unit cell*. Now if we use all the 20 atomic coordinates >> of previous calculation and make *all of them inequivalent by changing >> the space group to Primitive* then whether the calculation will give the >> same results as earlier calculation??.....I am asking this question >> because the structure (in Xcrysden) seems to be different......... >> > > A static calculation (one scf-cycle) must give you the same result, yes. It > will only take more time, because one can profit less from symmetry. > > If you allow geometry optimization, the final geometry might be different, > however: perhaps an atom that is not longer constrained by symmetry might > want to move to a different place. > > In order to convince yourself whether or not both structures are identical, > it is much cheaper to inspect the neighbours rather than performing an scf > cycle. Do 'x nn' for both structures, and compare the distances in > case.outputnn. > > Stefaan > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > -- Shamik Chakrabarti Research Scholar Dept. of Physics & Meteorology Material Processing & Solid State Ionics Lab IIT Kharagpur Kharagpur 721302 INDIA -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20101210/7fc00c7b/attachment.htm>