SSH-HAMILTONIAN DESCRIPTION OF THE ELECTRONIC-STRUCTURE AND VIBRATIONAL PROPERTIES OF POLYPARAPHENYLENE VINYLENE

We present the parameterization of a Su-Schrieffer-Heeger (i.e., Huckel plus sigma compressibility) Hamiltonian to describe the molecular geometry and the electronic structure of undoped and doped polyparaphenylene vinylene, one of the currently most studied conjugated polymers. We then apply a perturbation technique to obtain a qualitative insight into the vibrational structure of the electron-lattice coupled system. Analysis is focused on the localized modes appearing around the bipolaron defects.