I believe it's ok if you have >100 CPU, I guess you can relax this system 1~2 weeks, if you set Meshcutoff in 150Ry.
On Thu, Jun 23, 2011 at 10:11 PM, Alexander Vozny <[email protected]> wrote: >> can somebody tell the maximum Si system size with DZP basis set which >> Siesta can handle? >> Relax in less than a month? Only Gamma k-point. Using cluster, parallel >> calculations. > > Ruslan, > I did a graphene flake (i.e. lots of vacuum) with more than 600 atoms, 300Ry > cutoff and DZP, on 6 to 18 processors. It was slow, but converged in about a > month. > If you have a bulk Si (i.e. no vacuum) it could be faster (or at least less > memory demanding). > Try to relax using spin-unpolarized calculation first and only then continue > with spin, if required. > Alex. >
