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? Thanks, Klaus
