Molecular dynamics (MD) simulation has been used for the computation of the far infrared absorption coefficient of CCl4, with an excellent accord with experimental results at all frequencies. Nonadditive polarization interactions have been implemented with the chemical potential equalization method, which requires the gas phase values of the octupole moment and mean polarizability tenser. It is shown that the absorption coefficient constitutes an exacting probe of interaction potentials, strongly favoring a physically reasonable set of atomic charges.