Solvation structure of coumarin 1 in acetonitrile: role of the electrostatic solute-solvent potential

A molecular dynamics simulation study of a coumarin 1 molecule solvated in acetonitrile, in its S-0 and S-1 electronic states, is presented. Three solute-solvent interaction potentials, all containing the same Lennard-Jones component but different electrostatic interactions, have been considered. The structure of the solvent around the large dye solute strongly depends on the electrostatic solute-solvent potential, illustrating the crucial role of the local electric field. An accurate description of the charge distribution of the solute is therefore necessary to describe correctly the solute-solvent structure and the solvation energy. (C) 1998 Elsevier Science B.V.