Adiabatic ab initio time-dependent density-functional theory employing optimized-effective-potential many-body perturbation theory potentials

A diagrammatic formalism for taking functional derivatives from the ab initio optimized effective potential, many-body perturbation theory (OEP-MBPT), exchange-correlation potentials is developed. Using this technique the frequency-independent (adiabatic approximation) kernel, corresponding to the second-order approximation OEP-MBPT(2) exchange-correlation potential is derived. The structure of the kernel is discussed and some initial numerical tests presented. The complexity of the computational procedure raises the question of what is warranted for a rigorous, ab initio approach that retains the one-particle structure of density functional theory compared to wave function approaches for excited states.