Graphics Processing Unit acceleration of the Random Phase Approximation in the projector augmented wave method

Abstract The Random Phase Approximation (RPA) for correlation energy in the grid-based projector augmented wave ( gpaw ) code is accelerated by porting to the Graphics Processing Unit (GPU) architecture. The acceleration is achieved by grouping independent vectors/matrices and transforming the implementation from being memory bound to being computation/latency bound. With this approach, both the CPU and GPU implementations have been enhanced. We tested the GPU implementation on a few representative systems: molecules (O 2 ), bulk solids (Li 2 O and MoO 3 ) and molecules adsorbed on metal surfaces (N 2 /Ru(0001) and CO/Ni(111)). Improvements from 10 × to 40 × have been achieved (8-GPUs versus 8-CPUs). A realistic RPA calculation for CO/Ni(111) surface can be finished in 5.5 h using 8 GPUs. It is thus promising to employ the non-self-consistent RPA for routine surface chemistry simulations.