  Quasiparticle self-consistent many-body perturbation theory (MBPT) methods
that update both eigenvalues and eigenvectors can calculate the excited-state
properties of molecular systems without depending on the choice of starting
points. However, those methods are computationally intensive even on modern
multi-core central processing units (CPUs) and thus typically limited to small
systems. Many-core accelerators such as graphics processing units (GPUs) may be
able to boost the performance of those methods without losing accuracy, making
starting-point-independent MBPT methods applicable to large systems. Here, we
GPU accelerate MOLGW, a Gaussian-based MBPT code for molecules, with open
accelerators (OpenACC) and achieve speedups of up to 9.7x over 32 open
multi-processing (OpenMP) CPU threads.
