THEORETICAL STUDIES FOR SECOND HYPERPOLARIZABILITIES OF ALTERNANT AND CONDENSED-RING CONJUGATED SYSTEMS .2.

摘要

Alternant and condensed-ring conjugated systems are expected to have large electron correlation and structure dependencies of the second hyperpolarizabilities (gamma). For example, cation radical triafulvalene exhibits a large negative gamma at the Hartree-Fock (HF) level contrary to a large positive one at the Muller-Plesset second-order (MP2) level. In this paper, we investigate gamma's for different charged states (neutral, ion radical and di-ion states) of pentalene and triafulvalene to reveal their electron correlation dependencies up to the Muller-plesset fourth order. [References: 4]