Finite‐field calculations of molecular polarizabilities using field‐induced polarization functions. II. Second‐ and third‐order perturbation correlation corrections to the coupled Hartree–Fock polarizability of HF

Abstract

AbstractCorrelation corrections to coupled Hartree–Fock (CHF) static dipole polarizabilities and dipole moment of the HF molecule are calculated using third‐order Rayleigh–Schrödinger perturbation theory with Møller–Plesset partitioning (RSMP) in a finite‐field procedure. Computations are also made for the dipole moment and polarizability derivatives at the equilibrium internuclear separation. Three different basis sets using contracted Gaussian orbitals augmented by field‐induced diffuse polarization functions have been employed to investigate the nature of variation of the properties under study, and the importance of field‐induced diffuse polarization functions is discussed. [2/1] Padé approximants are used to accelerate the convergence of the properties. The correlated dipole moment and polarizability values are in excellent agreement with the existing theoretical and experimental values. The dipole moment derivative is in perfect agreement with the existing correlated value. However, the polarizability derivatives at SCF and correlated levels differ appreciably from the existing SCF values and represent as improvement.