Simulating realistic features of chemical and materials systems with massively parallel many-body perturbation theory calculations

With experiments obtaining increasingly fine resolution in time, energy, and position, there is a growing need for high-fidelity calculations that can match this rapidly improving resolution. Many-body perturbation theory is one approach that has had significant successes in the accurate simulation of the optoelectronic properties of many materials classes and also of surface chemistry. These methods have traditionally been applied to comparatively simple materials with relatively small numbers of atoms and atom types in a simulation cell, but increasing computing power allows for calculations on systems with hundreds and evens thousands of atoms in a simulation cell. In this talk we will discuss our work on simulating the electrochemical oxygen reduction reaction (ORR) on a system of FeN₄clusters in graphene using the many-body random phase approximation (RPA) and including the effects of zero-point energy, vibrational entropy, solvation, and applied bias. We will also discuss calculations using the many-body GW-Bethe Salpeter equation (GW-BSE) approach to calculate the optoelectronic properties of complex materials including double perovskites.