Molecular dynamics simulations of local field factors

In the present work, the authors evaluate a scheme based on molecular dynamics to derive local field factors. These are given without any assumption of a cavity by fitting the Langevin functions to the order parameters obtained from the molecular dynamics simulations. The local field factors so obtained, with the detailed chromophore-solvent interactions and solvent structures taken into account, are much smaller than those calculated from the conventional Onsager and Lorentz models. A numerical demonstration is given for two typical organic chromophore molecules, p-nitroaniline and p-nitro-N,N-dimethylaniline dissolved in chloroform. (c) 2007 American Institute of Physics.