Ab initio analytic polarizability, first and second hyperpolarizabilities of large conjugated organic molecules: Applications to polyenes C 4H6 to C22H24

The static dipole polarizability and second hyperpolarizability tensors are calculated for polyene systems via ab initio coupled-perturbed Hartree-Fock theory. The effect of basis set augmentation on the calculated properties is explored for C₄H₆ and example basis sets are used to calculate the polarizability and second hyperpolarizability for the longer polyenes: C₆H8, C₈H₁₀, C₁₀H ₁₂, C₁₂H₁₄, C₁₄H₁₆,C ₁₆H₁₈, C₁₈H₂₀, C₂₀H ₂₂, C₂₂H₂₄. Results for the finite polyenes are extrapolated to predict the unit-cell polarizability and second hyperpolarizability of infinite polyacetylene. The working equations which take advantage of the 2n + 1 theorem of perturbation theory for calculating up to the second hyperpolarizability are given, and their implementation is briefly discussed. In particular it is shown that the implementation is readily amenable to parallel processing.