Coupled-Cluster Theory Revisited. Part I: Discretization

TL;DR

This paper develops a rigorous mathematical framework for discretization schemes in Coupled-Cluster methods, unifying single-reference and multireference approaches using graph-based concepts to improve understanding and implementation.

Contribution

It introduces a comprehensive, rigorous framework for discretization in Coupled-Cluster methods, including multireference approaches, using graph-based concepts.

Findings

Unified description of Coupled-Cluster discretization schemes

Derivation of single-reference and multireference equations

Enhanced transparency in Coupled-Cluster method analysis

Abstract

In a series of two articles, we propose a comprehensive mathematical framework for Coupled-Cluster-type methods. These methods aim at accurately solving the many-body Schrodinger equation. In this first part, we rigorously describe the discretization schemes involved in Coupled-Cluster methods using graph-based concepts. This allows us to discuss different methods in a unified and more transparent manner, including multireference methods. Moreover, we derive the single-reference and the Jeziorski-Monkhorst multireference Coupled-Cluster equations in a unified and rigorous manner.