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It has been possible to calculate solvent-induced two-photon absorption cross sections for a push-pull molecule in solutions. The two-photon cross sections of the investigated push-pull polyene are quite insensitive to the choice of cavity shape.

The authors present derivation and implementation of the cubic response equations that govern nonequilibrium and equilibrium solvation. Solvent effects on the frequency dependent second hyperpolarizability have been discussed.

A revision of second harmonic and electro-optical responses for the water molecule in its liquid state are theoretically is presented. The experimentally observed sign change of the second harmonic response of water on liquefaction is reproduced using the supermolecular and semicontinum model for both equilibrium and nonequilibrium implementation.

Thefirst-order hyperpolarizability, β, has been calculatedfor a group of marine natural products, the makaluvamines. These compoundspossess a common cationic pyrroloiminoquinone structure that is substitutedto varying degrees. Calculations at the MP2 level indicate that makaluvaminespossessing phenolic side chains conjugated with the pyrroloiminoquinonemoiety display large β values, while breaking this conjugationleads to a dramatic decrease in the calculated hyperpolarizability.This is consistent with a charge-transfer donor-π-acceptor (D−π–A)structure type, characteristic of nonlinear optical chromophores.Dynamic hyperpolarizabilities calculated using resonance-convergenttime-dependent density functional theory coupled to polarizable continuummodel (PCM) solvation suggest that significant resonance enhancementeffects can be expected for incident radiation with wavelengths around800 nm. The results of the current work suggest that the pyrroloiminoquinonemoiety represents a potentially useful new chromophore subunit, inparticular for the development of molecular probes for biologicalimaging. The introduction of solvent–solute interactions inthe theory is conventionally made in a density matrix formalism, andthe present work will provide detailed account of the approximationsthat need to be introduced in wave function theory and our programimplementation. The program implementation as such is achieved bya mere combination of existing modules from previous developments,and it is here only briefly reviewed. [ABSTRACT FROM AUTHOR]