Effect of interchain interactions on nonlinear lattice relaxation processes in MX chains

The effect of interchain interactions on the stability of solitons and polarons in halogen-bridged mixed-valence metal complexes has been studied within the one-dimensional extended Peierls-Hubbard model. The adiabatic potential-energy surfaces have been computed within a mean-field approximation. It turns out that in the weak electron-phonon coupling case, both solitons and polarons exist stably and solitons form the soliton-antisoliton bound state, i.e., breather, for small interchain interactions, while only polarons exist stably for large interchain interactions.