Static polarizabilities and C6 dispersion coefficients using the algebraic-diagrammatic construction scheme for the complex polarization propagator

Abstract

An implementation of the damped linear response function, or complex polarization propagator, using the algebraic-diagrammatic construction (ADC) scheme has been developed and utilized for the calculation of electric-dipole polarizabilities and C6 dispersion coefficients. Four noble gases (He, Ne, Ar, and Kr), five n-alkanes (methane, ethane, propane, butane, and pentane), three carbonyls (formaldehyde, acetaldehyde, and acetone), and three unsaturated hydrocarbons (ethene, acetylene, and benzene) have been treated with the hierarchical set of models ADC(2), ADC(2)-x, and ADC(3/2), and comparison has been made to results obtained with damped linear response Hartree–Fock (HF) and coupled cluster singles and doubles (CCSD) theory as well as high-quality experimental estimates via the dipole oscillator strength distribution approach. This study marks the first ADC calculations of C6 dispersion coefficients and the first ADC(3/2) calculations of static polarizabilities. Results at CCSD and ADC(3/2) levels of theory are shown to be of similar quality, with electron correlation effects increasing the molecular property values for all calculations except CCSD considerations of ethene and acetylene (attributed to an overestimation of bond electron density at HF level of theory). The discrepancies between CCSD and ADC(3/2) are partially due to ADC overestimating anisotropies, and discrepancies with respect to experimental values are partially due to the lack of zero-point vibrational effects in the present study.