We have developed an highly efficient electronic structure code, for parallel computers using message passing. The algorithm takes advantage of the natural parallelism in quantum chemistry problems to obtain very high performance even on a large number of processors. Most of the terms which scale cubically with respect to the number of atoms have been eliminated allowing the treatment of very large systems. It uses one of the most precise versions of Density Functional Theory, namely Self-Interaction Corrected Density Functional Theory. On a 6 processor Silicon Graphics Symmetric Multiprocessor based on the MIPs R8000 microprocessor, we obtain a performance of 6.3 Gflops per million dollar.

With a new and intrinsically parallel algorithm for tight binding molecular dynamics we obtain a performance of 9.4 Gigaflops per million dollar on a cluster of 8 Hewlett Packard workstations in a simulation of 216 Silicon atoms. One time step with this new algorithm takes as much time for the 216 atom system as one time step with a conventional algorithm on a NEC-SX3 supercomputer. In addition, the linear sealing of new algorithm allows us to calculate systems of unprecedented size which are not any more accessible by the combination of standard algorithms and vector supercomputers.>