PeIGS 3.0

## Parallel Eigensolver for Dense Real Symmetric Generalized and Standard eigensystem problems

## PeIGS 3.0 Parallel Performance

Feature that are found together elsewhere: Inverse iteration using Dhillon-Parlett-Fann's parallel algorithm (fast uniprocessor performance and good parallel scaling) Guaranteed orthonormal eigenvectors in the presence of large clusters of degenerate eigenvalues True Packed Storage Smaller scratch space requirements |
Full eigensolution performed on a matrix generated in a charge density fitting procedure (966 fitting functions for a fluorinated biphenyl). |

#### The research and prototype work was performed in part under the auspices of the Grand Challange Computational Chemistry Project of the High Performance Computing and Communications Program of the Office of Scientific Computing, U.S. Department of Energy under contract DE-AC066-76RLO 1830 with Battelle Memorial Institute which operates the Pacific Northwest National Laboratory.

#### Software support of PeIGS version 3 was supported by the U. S. Department of Energy under Contract DE-AC06-76RLO 1830 under EMSL operations. EMSL operations are supported by the DOE's Office of Biological and Environmental Research. The Pacific Northwest National Laboratory is operated by Battelle Memorial Institute.

#### Implementation of PeIGS version 1 and 2 was supported by EMSL Construction Project WB4.5.3.1 in support of computational chemistry software under contract DE-AC066-76RLO 1830 with Battelle Memorial Institute which operates the Pacific Northwest National Laboratory under DE-AC066-76RLO 1830

#### Please e-mail your questions to fanngi@ornl.gov