A Finite Field Algorithm for GW Calculations Beyond the Random Phase Approximation*

The GW approximation is widely used to compute electronic structure of molecules and materials. Most GW calculations are performed within the random phase approximation (RPA). In this talk I will present our recent development of a finite field algorithm to evaluate density response functions beyond the RPA. The algorithm does not require explicit evaluation of empty electronic states and leads to highly scalable calculation on high performance architectures. The algorithm was implemented by coupling the Qbox [qboxcode.org] and WEST [west-code.org] codes. I will present results for molecules, solids and solid-solid interfaces and discuss vertex corrections in GW calculations.