Multiscale coupled Maxwell's equations and polarizable molecular dynamics simulation based on charge response kernel model.

A computational scheme of coupled Maxwell's equations and polarizable molecular dynamics simulation has been developed based on a multi-scale model to describe the coupled dynamics of light electromagnetic waves and molecules in crystalline solids, where the charge response kernel model is employed to incorporate electronic polarization of the molecules. The method is applicable to electronically non-resonant light-matter interaction systems that involve atomic motions in spectroscopy and photonics. Since the scheme simultaneously traces the light propagation in a medium on a macroscopic scale and the microscopic molecular motion under the light electric field, this enables us to treat the experimental setup and mimic its measurement process. As the first applications, we demonstrate three numerical examples of basic spectroscopies of an ice crystalline solid: simulations of reflection and transmission of visible light, infrared absorption measurement, and stimulated Raman scattering measurement. These examples show the detailed behaviors of the interacting light fields and molecules in the spectroscopic processes.