On Wed, Jun 8, 2011 at 7:34 AM, Klaus Zimmermann < klaus.zimmermann at physik.uni-freiburg.de> wrote:
> Hi Jed, Hi Matthew, > > thanks for your quick responses! > > On 06/08/2011 02:23 PM, Jed Brown wrote: > > On Wed, Jun 8, 2011 at 14:17, Matthew Knepley <knepley at gmail.com > > <mailto:knepley at gmail.com>> wrote: > > > > However, you might look at Elemental > > (http://code.google.com/p/elemental/) which solves the complex > > symmetric eigenproblem and is very scalable. > > > > > > Note that Elemental is for dense systems. > > > > > > To solve your problem, it's important to know where it came from. The > > average number of nonzeros per row doesn't tell us anything about it's > > mathematical structure which is needed to design a good solver. > > We are doing quantum mechanical ab initio calculations. The Matrix stems > from a two particle Hamiltonian in a product basis. Thus we have basis > vectors S_{nm}. The sparseness is now due to the fact that the matrix > element <S_{nm}|H|S_{n'm'}> can only be non-zero if |n-n'|<4 and |m-m'|<4. > > Does this help or do you need more information? Like the matrix > construction code? > This does not just sound sparse, it sounds banded. Is this true? If so, you can use dense, banded solvers instead. Matt > Thanks, > Klaus > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110608/8c9238b5/attachment.htm>
