Perspective on Coupled-cluster Theory. The evolution toward simplicity in quantum chemistry

Abstract

Coupled-cluster theory has revolutionized quantum chemistry.

Perspective: multi-configurational methods in bio-inorganic chemistry

“…These two methods are accurate since they capture the main part of the so-called dynamical correlation well. In case even more accurate methods are required for dynamical correlation, the hierarchy of coupled cluster (CC) methods 12 can be applied. Yet, DFT methods are much more efficient, making them more popular.…”

An Innovative Approach for Precise Identification of the Lowest Unoccupied Molecular Orbital Using the Parametric Equation of Motion

“…For instance, when using a highly diffuse basis set, the energy for the lowest empty molecular orbital (MO) will be almost zero, making it unreliable. In Post-SCF − theories such as configuration interaction (CI), coupled cluster (CC), and perturbation theory, electron correlation effects beyond the mean-field approximation are taken into account to provide more accurate descriptions of molecular systems. Among these theories, the lowest unoccupied molecular orbital (LUMO) plays a crucial role in theoretical analyses and practical applications.…”