Complex polarization propagator method for calculation of dispersion coefficients of extended pi-conjugated systems: The C-6 coefficients of polyacenes and C-60

摘要

The frequency-dependent polarizabilities and the C-6 dipole-dipole dispersion coefficients for the first members of the polyacenes namely benzene, naphthalene, anthracene, and naphthacene as well as the fullerene C-60 have been calculated at the time-dependent Hartree-Fock level and the time-dependent density-functional theory level with the hybrid B3LYP exchange-correlation functional. The dynamic polarizabilities at imaginary frequencies are obtained with use of the complex linear polarization propagator method and the C-6 coefficients are subsequently determined from the Casimir-Polder relation. We report the first ab initio calculations of the C-6 coefficients for the molecules under consideration, and our recommended value for the dispersion coefficient of the fullerene is 101.0 a.u. (c) 2005 American Institute of Physics.