Improving the Performance of Numerical Algorithms for the Bethe‐Salpeter Eigenvalue Problem

The Bethe‐Salpeter eigenvalue problem arises in the computation of the electronic structure of many‐body physical systems. The resulting matrix is complex, admits a certain block structure and can become extremely large. This raises the need for structure‐preserving algorithms running in parallel on high performance compute clusters. In this paper we examine how a recently proposed direct method given in the BSEPACK library can be improved using eigenvalue solvers from the ELPA library. For large matrices a runtime reduction of up to 80% is achieved.