Electric dipole polarizabilities and C 6 dipole-dipole dispersion coefficients for alkali metal clusters and C 60

Abstract

The frequency dependent polarizabilities of closed-shell alkali metal clusters containing up to ten lithium, potassium, and rubidium atoms have been calculated using the linear complex polarization propagator approach in conjunction with Hartree – Fock and Kohn – Sham density functional theory. In combination with polarizabilities for C₆₀ from a previous work [J. Chem. Phys. 123, 124312 (2005)], the C₆ dipole-dipole dispersion coefficients for the metal cluster-to-cluster and cluster-to-buckminster fullerene interactions are obtained via the Casimir – Polder relation. The B3PW91 results for the polarizabilities and dispersion interactions of the alkali metal dimers and tetramers are benchmarked against couple cluster calculations, and the whole series of calculations are compared against the corresponding work on sodium clusters [J. Chem. Phys. 125, 124306 (2006)]. The error bars of the reported theoretical results for the C₆ coefficients are estimated to be 8%.