What I always do is try and stick with a similar density of points in reciprocal space. Hence if you used a grid of LxMxN for a 1x1x1 cell then I would use (L/P)x(M/Q)x(N/R) for a PxQxR supercell.
Note: at the top of case.kgen you can see what the grid is, and this is a better measure than "2000 k points" which is not what the code really produces. You can also specify the grid. On Fri, Feb 17, 2012 at 1:09 PM, Parker, David S. <parkerds at ornl.gov> wrote: > Saba, generally if I am running a system that is not big, such as the > Heuslers or supercells thereof, 2000 k points in the full BZ is enough. For > bigger systems the number of k-points will be limited by your patience and > access to parallel computing resources, but for a basic scf calc I very > rarely use more than 2000 k points. I have recently run an mBJ calculation on > a structure that is a variant of the half-Heusler. without problems. ?There > should be no problem running LSDA+so calcs as you ask, when I do these I > often incorporate so from the start. ?Best, David Parker > > > On 2/17/12 1:54 PM, "Saba Sabeti" <raskolnikof6028 at yahoo.com> wrote: > > Dear all, > Thanks to Mr Fecher for his attention to my previous question, which was > solved just after posing the question. > Now, I'm going to ask you all some other questions and I would be so thankful > if you help me to solve them: > > 1. How many k-points are needed for a supercell calculation like AxB1-xCD > when x=1/4-3/4, and while I use 5000 k-points for ACD and BCD? > ?2. Can I do LSDA+so calculations like ACD(a half-heusler) case,I mean: > initialize+run scf > save case_nrel > initso > run scf+so > 3. And a calculation similar to which has come in userguide for Becke-Johnson? > best regards > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien -- Professor Laurence Marks Department of Materials Science and Engineering Northwestern University www.numis.northwestern.edu 1-847-491-3996 "Research is to see what everybody else has seen, and to think what nobody else has thought" Albert Szent-Gyorgi
