Electric Dipole Polarizabilities And C_6 Dipole-dipole Dispersion Coefficients For Alkali Metal Clusters And C_(60)

摘要

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 C_(60) from a previous work [J. Chem. Phys. 123, 124312 (2005)], the C_6 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 C_6 coefficients are estimated to be 8%.