Self-Consistent RPA from a Coupled Cluster Wave Function Perspective

TL;DR

This paper presents a new derivation of Self-Consistent RPA using a Coupled Cluster wave function, providing a detailed analysis and evaluation of the method's performance on solvable models.

Contribution

It introduces an exact killing operator for the Coupled Cluster ground state, enabling a consistent rederivation of Self-Consistent RPA and a thorough performance assessment.

Findings

Quantitative evaluation of the method on solvable models

Introduction of an exact killing operator for the CC wave function

New perspective on the approximation scheme in RPA

Abstract

Self-Consistent RPA is rederived in a consistent way with the help of the Coupled Cluster ground state wave function truncated at the two body level. An exact killing operator for this wave function is introduced allowing for a detailed discussion of the approximation scheme. Several exactly solvable models are reanalyzed under this new perspective giving raise to a quantitative evaluation of the performances of this many body method.