In this communication, we apply a recently presented nonperturbative molecular orbital approach (Th. Koslowski, J. Chem. Phys. 113 (2000) 10703) to the energetics of small polaron formation and hopping in tungsten bronzes in the regime of small excess electron concentrations. The electronic structure of the system is described by a tight-binding Hamiltonian, including a nonretarded reaction field to account for the dielectric polarizabilty of the solid. The resulting model is solved self-consistently, leading to a localized excess electron charge distribution. The potential energy curve for polaron hopping is presented and analyzed in terms of a two-site donor-acceptor model.
Print ISSN: 0942-9352
Volume: 215, 12/2001
Pages: 1625