Solving the Bethe-Salpeter equation on massively parallel architectures

The last ten years have witnessed fast spreading of massively parallel computing clusters, from leading supercomputing facilities down to the average university center. Many companies in private sector undergone a similar evolution. In this scenario, seamless integration software and middleware libraries is key ingredient ensure portability scientific codes guarantees them an extended lifetime. work, we describe ChASE library, modern eigensolver, into existing legacy code for first-principles computation optical properties materials via solution Bethe-Salpeter equation polarization function. Our numerical tests show that, as result integrating parallelizing reading routine, experiences remarkable speedup greatly improved scaling behavior on both multi- many-core architectures. We demonstrate that such modernized BSE will, by fully exploiting architectures file systems, enable domain scientists accurately study complex material systems were not accessible before.