Mn. Kobrak et S. Hammes-schiffer, Molecular dynamics simulation of proton-coupled electron transfer in solution, J PHYS CH B, 105(42), 2001, pp. 10435-10445
A new approach for the molecular dynamics simulation of proton-coupled elec
tron transfer reactions in solution is presented. The solute is represented
by a four-state valence bond model, and the solvent is described by explic
it solvent molecules. The nuclear quantum effects of the transferring hydro
gen are incorporated with a procedure based on a series of purely classical
molecular dynamics simulations. The resulting mixed electronic/vibrational
free energy surfaces depend on two solvent reaction coordinates correspond
ing to electron and proton transfer. This approach is shown to be equivalen
t to adiabatic mixed quantum/classical molecular dynamics, in which the nuc
lear quantum effects are included during the simulation, under well-defined
, physically reasonable conditions. The results of the application of this
approach to a model system are compared to those from a previous study base
d on a dielectric continuum treatment of the solvent. In addition, specific
molecular motions of the solvent associated with proton-coupled electron t
ransfer are identified, and solvent configurations that couple the proton a
nd electron transfer reactions are characterized. This methodology may be i
mplemented using commercial molecular dynamics software packages with littl
e or no modification to the existing programs.