Quasi-one-dimensional approximation in the HMO model of polymethine dyes
In the framework of the Hueckel molecular orbital (HMO) model, an analytical method has been elaborated which enables calculation of energy levels and wave functions for polymethine dye molecules with arbitrary end groups characterized by two effective additive parameters. The method represents a generalization of the known long-chain approximation (LCA) manipulating only frontier pi-MOs and yields analytical relations for molecular characteristics based on all occupied dye pi-MOs.
quasi-one-dimensional approximation long-chain approximation polymethine compounds green's functions atomic charges bond orders