Effect of configurational composition of the wave function on calculated dipole polarizability of molecules

On the basis of the π-electron approximation we have investigated the dependence of the calculated dipole polarizability of molecules on the configurational composition of the variational wave function. The values which were closest to the results of complex configurational interaction were obtained for sets including the single-determinant Hartree-Fock function and all the bonding doubly excited configurations constructed from the localized MO, and also from the complete set of singly and doubly excited configurations.