At this point of the study, our question is how far we have to go up to higher-order excited-state molecular interactions to improve our understanding of the photobiological color-tuning mechanism. Therefore, the subject of the present study is (i) to derive an operator which defines the excitation energy (presently at the Hartree-Fock/CIS level), (ii) to derive first-order interacting space (FOIS) of the operator, and (iii) to decompose the correction into intermolecular interactions. We applied the present method to the three excited states, which are the n-π* and π-π* excited states of s-trans-acrolein (ACL) and the π-π* excited state of methylenecyclopropene (MCP) in water clusters. Figures 1 and 2 show the magnitude of the second-order energy contributions from each fragment. Solvents at closer distance to the solute tend to give larger contributions. The magnitude of the polarization effect depends on the change in the dipole moment upon the transition.

Quantum mechanical molecular interactions for calculating excitation energy in molecular environments: A first-order interacting space approach

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.