Many-body interactions and the electric response of hydrogen-bonded molecular chains

Quantitative analysis of the impact of intermolecular interactions on the nonlinear electric response of hydrogen-bonded molecular chains has been performed. In particular, the theoretical description of cooperative effects (nonadditivity) based on the many-body calculations is provided. Nonlinear optical response of H-bonded chains (linear and zigzag HF⋯(HF)n, linear H2CO⋯(H2CO)n and H3N⋯(HF)n, where n = 1–4) has also been studied. Values of the static electric dipole moment, polarizability and first-order hyperpolarizability have been calculated and analyzed at the MP2 level of theory using Dunning’s correlation-consistent basis set. The site–site function counterpoise (SSFC) method has been applied in order to avoid basis set superposition error (BSSE). Particularly interesting observations have been drawn in the case of first-order hyperpolarizability.