In plain words: Molecular systems are composed of a very large number of atoms and molecules. But, often, only one or two are particularly interesting in that they are the ones that determine whether a chemical reaction or molecular motion takes place. So it is natural to ask the question of the extent to which all the details of the other atoms or molecules is important. One popular approach treats the forces from such molecules only in terms of their statistical properties. Our group is pursuing this approach to understand far from equilibrium molecular motions.

Stochastic Potentials

Relevant references are:

• R. Hernandez and F. L. Somer; "Stochastic dynamics in irreversible nonequilibrium environments. 1. The Fluctuation-Dissipation Relation," J. Phys. Chem. B 103, 1064 (1999). (abstract, doi:10.1021/jp983625g)
• E. Hershkovitz and R. Hernandez; "Fast numerical integrator for stochastic differential equations with nonstationary multiplicative noise," J. Phys. Chem. A 105, 2687-2693 (2001). (In the William H. Miller Festschrift issue.) (doi:10.1021/jp0037044)
• T. D. Shepherd and R. Hernandez; "Chemical reaction dynamics with stochastic potentials beyond the high-friction limit," J. Chem. Phys. 115, 2430-2438 (2001). (doi:10.1063/1.1386422)
• T. D. Shepherd and R. Hernandez; "Activated dynamics across aperiodic stochastic potentials," J. Phys. Chem. B 106, 8176-8181 (2002). (In the John C. Tully Festschrift issue.) (doi:10.1021/jp020620h)
• T. D. Shepherd and R. Hernandez; "An optimized mean first passage time approach to obtaining rates in activated processes," J. Chem. Phys. 117, 9227-9233 (2002). (doi:10.1063/1.1516590)
• J. M. Moix and R. Hernandez; "Dissipating the Langevin equation in the presence of an external stochastic potential," J. Chem. Phys. 122, 114111 (2005). (cond-mat/0501327, doi:10.1063/1.1870875)