Abstract
The study of more and more complex systems, like electronic structures, necessitates to solve numerically large eigenvalue problems. Due to the large size of their matrix representation, the utilization of traditionnal resolution methods are inadequate. With the development of parallel computers and iterative methods, some of these problems can be solved.

This study must be included into a large project, consisting in parallelizing the DFT2000 code of total energy computation and must serve to analyze the efficiency of the parallelization of iterative methods on shared and distribued memory computers.

We use a modified block Davidson's iterative method and parallelize it using the MPI (Message Passing Interface) Standard and Fortran 90. The efficiency of parallelization on the two computer architectures are presented.