The basis for molecular dynamics simulations of the electron transfer between multiple redox species and a metal electrode is developed using the Anderson-Newns approach to model the effect of the electronic degrees of freedom. As an example, the free energy surface for 2 redox species coupled to the metal surface and with each other is computed via two dimensional umbrella sampling. The resulting free energy surface is found to be qualitatively in agreement with an analytic model for such a process [Y. Boroda, A. Calhoun, and G. A. Voth, J. Chem. Phys. 107, 8940 (1997)], with relatively minor quantitative disagreement.