Department of Chemical Sciences
School of Natural Sciences

March 21, 2018 at 2.30 pm in AG-80

Title :

Variational Random Phase Approximation Method for Accurate Ionization Potentials and Interaction Energies

Abstract :

A critical and outstanding challenge of electronic structure method development is to deliver both accurate total energy differences and quasiparticle spectra. I will address this challenge using a generalized Kohn-Sham (GKS) approach that variationally minimizes the random phase approximation (RPA) ground-state energy as a functional of the one-particle density matrix. The GKS-RPA approach enables highly accurate predictions of all observables from derivatives of a single variationally stable energy functional, and leads to remarkable advancements. Intermolecular binding-energies and quasiparticle spectra from GKS-RPA improve significantly upon those from state-of-the-art post-Kohn-Sham RPA or G0W0 theory. Anions, which are often unstable and poorly described by semi-local density functional approximations, are well described within GKS-RPA. Core ionization energies, which are traditionally hard to compute, can be accurately estimated using GKS-RPA; pilot applications for modeling solvation effects in conjunction with X-ray photoelectron spectroscopy will be discussed. Overall, the GKS scheme alleviates some of the most serious problems with semi-local density functional approximations, and paves the way for a new generation of electronic structure methods.


  1. G. Chen, V. K. Voora, M. Agee, S. Balasubramani, and F. Furche. “Random phase approximation methods”, Annu. Rev. Phys. Chem., 2017, 68, 421. 
  2. V. K. Voora, S. G. Balasubramani, and F. Furche. “Variational Generalized Kohn-Sham Approach Combining Random Phase Approximation and Green’s Function Methods”, https://escholarship.org/uc/item/7gf3h1h9.