A ScaLAPACK-based Parallelization of LSDALTON

Linear Scaling DALTON (LSDALTON) is a powerful molecular electronic structure program that is the focus of software optimization projects in PRACE 1IP-WP7.2 and PRACE 1IP-WP7.5. This part of the project focuses on the introduction of parallel diagonalization routines from the ScaLAPACK library into the latest MPI version of LSDALTON. The parallelization work has involved three main tasks: i) Redistribution of the matrices assembled for the SCF cycle from a serial / distributed state to the two dimensional block-cyclic data distribution used for PBLAS and ScaLAPACK; ii) Interfacing of LSDALTON data structures to parallel diagonalization routines in ScaLAPACK; iii) Performance testing to determine the favoured ScaLAPACK eigensolver methodology.