CALCULATION OF SOLVATION FREE-ENERGIES USING A DENSITY FUNCTIONAL/MOLECULAR DYNAMICS COUPLED POTENTIAL

Recently there has been much interest in the development of methods which couple quantum mechanical and molecular mechanical computational models. Herein, we report the first coupling of a density functional Hamiltonian with a molecular mechanical method. The AMBER force field was coupled with a density functional Hamiltonian as implemented in the deMon program. Test calculations of solvation energies were carried out for a small group of ions. We find that our coupled potential method slightly underestimates the solvation energy of the chloride ion while it overestimates the solvation energy of the other ions studied, Nonetheless, this method will allow a chemist to study condensed-phase systems at a level of accuracy currently not available.