Towards highly scalable GW calculations*

The GW and Bethe-Saltpeter Equation (GW-BSE) approach is an accurate and useful method beyond DFT to describe excited states of materials. However over the past few decades, most {\it ab initio} GW calculations used have been confined to small units of cells of bulk-like materials due to the extreme computational demands of the approach. We will present our collaborative efforts to develop new software that permits large scale GW calculations more efficiently: our GW software is interfaced with the ab initio plane wave pseudopotential OpenAtom software (http://charm.cs.uiuc.edu/OpenAtom/) that uses the Charm++ parallel framework. Here, we focus on describing our work on computing the static (so called ``COHSEX’’) GW self-energy. We describe the advantages of our real-space approach for quasi-particle calculations and provide information on scaling behavior of the resulting algorithms.