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 center dot center dot center dot(HF)(n), linear H2CO center dot center dot center dot(H2CO)(n) and H3N center dot center dot center dot(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. (C) 2011 Elsevier B.V. All rights reserved.