Adaptive time-dependent coupled cluster method for multiparticle wavepacket dynamics

TL;DR

This paper introduces an adaptive, time-dependent coupled cluster method that enhances the simulation of complex multiparticle wavepacket dynamics with high accuracy by incorporating variational principles and time-dependent functions.

Contribution

It presents a novel, systematic, and size-consistent adaptive coupled cluster approach that generalizes existing methods and is suitable for efficient computer implementation.

Findings

Provides equations of motion for the method

Demonstrates the method's suitability for complex systems

Includes standard time-dependent Hartree-Fock as a special case

Abstract

A dynamical formulation of coupled cluster theory is derived using a variational principle. By allowing time-dependent single-particle functions, a high degree of adaptivity is introduced, allowing complex systems to be simulated with high accuracy. Equations of motion are derived which are shown to be suitable for computer implementation. The method, called adaptive time-dependent coupled cluster, is a strict generalization of the formulation used in standard coupled cluster response theory, and also represents a systematic hierarchy of size-consistent approximations, including standard time-dependent Hartree--Fock as a trivial case.