Analytic second derivatives in high-order many-body perturbation and coupled-cluster theories: Computational considerations and applications

Abstract

The history of analytic first- and second-derivative methods in quantum chemistry is discussed, with special emphasis given to approaches that are associated with electron correlation treatments based on many-body perturbation theory (MBPT) and the coupled-cluster (CC) approximation. The computational requirements of recently developed analytical second derivative methods for high-order MBPT and CC methods are discussed in detail and compared with those associated with finite-difference procedures. Applications of these techniques to the calculation of anharmonic force fields used to deduce equilibrium geometries and fundamental vibrational frequencies for polyatomic molecules are reviewed.