Time-Dependent Vibrational Coupled Cluster Theory With Static and Dynamic Basis Functions

Abstract

In recent decades, coupled cluster theory has proven valuable in accurately describing correlation in many-body systems, particularly in time-independent computations of molecular electronic structure and vibrations. This review describes recent advancements in using coupled cluster parameterizations for time-dependent wave functions for the efficient computation of the quantum dynamics associated with the motion of nuclei. It covers time-dependent vibrational coupled cluster (TDVCC) and time-dependent modal vibrational coupled cluster (TDMVCC), which employ static and adaptive basis sets, respectively. We discuss the theoretical foundation, including many-mode second quantization, bivariational principles, and various parameterizations of time-dependent bases. Additionally, we highlight key features that make TDMVCC promising for future quantum dynamical simulations. These features include fast configuration-space convergence, the use of a compact adaptive basis set, and the possibility of efficient implementations with a computational cost that scales only polynomially with system size.