Parallel task processing in ab initio electronic structure calculations

Abstract

In order to perform precise investigation of low-symmetry effects, a direct numerical method for electronic structure modeling has been proposed. The radial orbitals are split in accordance with the site symmetry of the ion in the crystal and its electronic structure is calculated with a nonspherical ab initio potential of nearest neighbours. The introduction of parallel techniques is discussed from two points of view. The physical model is based on an atomistic approach for solids which is totally equivalent to usual ab initio quantum chemistry approximations. `Non-effective' physical treatment becomes attractive computationally due to the possibility of solving, simultaneously and up to self consistency, a common equation duplicated many times with different parameters. Thus, parallel task processing on the set of equations for atomic shells together with message passing of single electron orbitals calculated in each process allows co-ordination of thousands of processors for the thousands of electrons in the crystal.