Singlet and triplet excited state electric dipole polarizabilities of conjugated hydrocarbons

First excited singlet and triplet electric dipole polarizabilities are reported. The π polarizability is calculated by means of a modified Rayleigh–Schrödinger perturbation theory and an SCF‐LCAO basis. The σ contribution is included by an additive scheme. The polarization of the σ electrons is partially accounted for through an empirical correction. Results compare satisfactorily with a configuration interaction perturbation calculation.