Time-dependent orbital-optimized coupled-cluster methods families for fermion-mixtures dynamics

TL;DR

This paper introduces five novel time-dependent orbital-optimized coupled-cluster methods for simulating fermion-mixture dynamics, offering a compact alternative to multiconfiguration methods with broad applicability.

Contribution

The paper develops and presents five new time-dependent orbital-optimized coupled-cluster methods capable of handling arbitrary fermion mixtures, including convergence to the CAS-SCF method.

Findings

Methods can converge to CAS-SCF

Applicable to systems with different fermion types

Derived equations maintain orbital invariance

Abstract

Five time-dependent orbital optimized coupled-cluster (TD-ooCC) methods, of which four can converge to the complete active space self-consistent-field method, are presented for fermion-mixtures with arbitrary fermion kinds and numbers. Truncation schemes maintaining the intragroup orbital rotation invariance, as well as equations of motion of CC amplitudes and orbitals, are derived. Present methods are compact CC-parameterization alternatives to the time-dependent multiconfiguration self-consistent-field method for systems consisting of arbitrarily different kinds and numbers of interacting fermions. Theoretical analysis of applications of present methods to various chemical systems are reported.