Using a tight-binding Hamiltonian we study the Peierls distorted form of polyaniline, the pernigraniline base polymer. Both bond order and ring torsional degrees of freedom are considered in the conformational relaxation. The geometrical and electronic structures of the localized excitations are calculated. Comparison with available optical and magnetic measurements is made. Particular emphasis is placed on the spectroscopic and magnetic features of neutral solitons.

• Received 4 June 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.1497