Variational–perturbational treatment for the polarizabilities of conjugated chains. I. Theory and linear-polarizabilities results for polyenes

Publisher Website
Google Scholar
Abstract
We use a perturbative density matrix treatment to investigate the behavior of the static polarizabilities α of linear conjugated chains CNHN+2, with respect to the chain length and to the presence of neutral and charged conjugation defects of soliton and polaron type. The molecules are described by the Pariser–Parr–Pople Hamiltonian; both closed and open shells are treated. It is shown that both the longitudinal component of α and the orientationally averaged linear polizability scale as different powers of N in each case. It is also shown how the present treatment can be considered as a generalization of standard variation–perturbation methods for the Hartree–Fock case.