[petsc-users] Advise on choice of iterative solver

[Klaus Zimmermann]

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