Starting from the last versions, Lumen officially support ELPA library:
https://elpa.mpcdf.mpg.de/ELPA_USED.html
ELPA is a library that to provide highly efficient eigenvalue solvers for Petaflop systems, and Lumen use it in the solution of the Bethe-Salpeter Equation. If you computer cluster has this library installed you can link it to Lumen to speed up your calculations.
Performance analysis on ELPA (and Slepc) used for the BSE solver (both on CPU and on GPU) can be found here: https://arxiv.org/abs/2504.10096
