Energy gradients and effective density differences in electron propagator theory

Abstract

Efficient calculations of adiabatic electron binding energies require gradients of ground and excited potential energy surfaces. These surfaces may be inferred from reference-state total energies and vertical electron binding energies of the electron propagator. Reference-state total energies from many-body perturbation theory may be derived from electron propagator theory and gradients of these expressions are already known. The missing information for final-state optimization therefore is provided here. Gradients of electron propagator poles (ionization energies and electron affinities) with respect to nuclear positions in the second-order, 2p-h Tamm-Dancoff and nondiagonal, renormalized, second-order approximations of electron propagator theory are derived. Effective electron density difference matrices corresponding to these poles are by-products of the derivations. © 2000 American Institute of Physics.