Molecular dynamics simulations of matrix trapped molecules

Abstract

The use of molecular dynamics (MD) to simulate the structure of trapping sites of molecules in cryogenic matrixes is surveyed, with an emphasis on work from the authors' laboratory. After commenting on the methods used to simulate the trapping of small symmetric molecules, recent attempts to use the method for medium sized molecules and clusters (about 20-30 atoms) are described. In particular, the study of low-symmetry molecules such as propyl-benzene, phenylpyrrole and pyrrolobenzonitrile are described. The structures of the sites help in understanding the spectra and photochemistry of these molecules in cryogenic matrixes. A complete simulation of the IR or UV spectra of trapped molecules requires a methodology for calculating the energy levels in a matrix, based on the structures obtained by MD. The current state of the art is briefly reviewed and possible pending advances are discussed.