Theoretical studies on hyperpolarizabilities of nitroxide species. III. Effects of intermolecular interactions of p-NPNN on the γ

The effects of intermolecular interactions of para-nitrophenyl nitronyl nitroxide (p-NPNN) in the crystal on the γ are investigated. The γʹs for two types of configurations, which exist in the β-phase crystal of p-NPNN, are examined by the coupled Hartree-Fock (CHF) calculations of cluster models involving up to tetramers. It is found that the intermolecular interactions in these configurations give different contributions to two large components of the γ.