The Hamiltonian for the dynamics of a structural defect in a linear hydrogen bonded system (e.g., one analogous to an excess proton in ice) is developed, including explicit expressions for the coupling between the defect and phonons. The nature of these couplings are discussed and the results of a minimal basis set SCF calculation on a model system presented. The coupling to the longitudinal phonons is found to be very strong. © 1969 Springer-Verlag.