Anisotropic oscillator strength of 1-hydronaphthyl radical in naphthalene single crystal

The absolute value of the optical absorption strength of the 539 nm intra-radical transition of the 1-hydronaphthyl radical in a naphthalene crystal was measured with light polarized along the a, b and c′ axes. The long and short axial components of the oscillator strength were determined by using the local field tensors obtained with several methods. It was found that the local field tensors obtained recently by Munn, assuming each molecule to be two polarizable points, yield good agreement between the molecular axial components of the oscillator strengths obtained experimentally and theoretically. The local field tensors obtained previously with the single point-dipole approximation were found to result in inconsistency.