A modular molecular dynamics quantum dynamics program for non-adiabatic proton transfers in solution

A new program for non-adiabatic mixed quantum dynamics (QD)/molecular dynamics (MD) simulations of a proton transfer is presented. This program consists on GROMOS96 as MD program and an ad hoc program to perform the dynamics of one or more quantum particles in a one or three-dimensional position representation. The quantum particles do not necessarily have to be protons. Various switches allow the use of different solutions of problems occurring at many levels of theory: the interaction of the protons with atoms of their environment, the proper handling of the time dependence of the state and potential of the proton, the reference points of the quantum coordinate in the classical configuration, the coherence and exchange between the classical and the quantum mechanical subsystems and the time evolution of the quantum mechanical state under the influence of a known potential. A protonizable water model has been developed and tested. (C) 1997 Elsevier Science B.V.