Coupled-Hartree-Fock calculations of the static third-order hyperpolarizabilities (??) in the chain direction for regular polydiacetylene and several donor (D)-acceptor (A) substituted polydiacetylene oligomers through C42H24 are carried out at the level of the INDO approximation. The modes of the variations in ?? with the increasing chain length are investigated for the different types of polydiacetylene systems. The ?? density analysis is carried out to elucidate the spatial characteristics of ??. Results for sufficiently long oligomers are extrapolated to an infinity of the chain length to predict the intrinsic ?? values per repeating unit of the polydiacetylenic chains. ?? 1991.
Nakano, M., Yamaguchi, K., & Fueno, T. (1991). Coupled-Hartree-Fock calculations of the third-order hyperpolarizabilities of substituted polydiacetylenes. Chemical Physics Letters, 185(5–6), 550–554. https://doi.org/10.1016/0009-2614(91)80258-Y