For example, the trajectory in Figure (a) attempted a back hopping from S1 to S2 at 99.5 fs. The potential energy gap was 0.22 eV. With the conventional kinetic energy reservoir, 3.68 eV of kinetic energy was available, and back hopping was allowed. With the reduced kinetic energy reservoir, the available kinetic energy would be only 3.68/72 = 0.05 eV, and the back hopping would be frustrated. Most back hoppings behave in this way. This same trajectory allowed 21 S1→S2 back hoppings, with a mean potential energy gap of 0.30 eV and mean available kinetic energy of 3.44 eV. With the reduced reservoir, only four of these hoppings would be allowed. This analysis demonstrates that the amount of kinetic energy available for back hopping with the conventional reservoir would unreasonably allow most back hopping events, while the reduced kinetic energy reservoir delivers a more balanced description of the nonadiabatic events.