We model the triplet triplet energy-transfer experiments from the Closs group [Closs, G. L., et al J. Am. Chem. Soc. 1988, 110, 2652] using a combination of Marcus theory and either Boys or Edmiston-Ruedenberg localized diabatization, and we show that relative and absolute rates of electronic excitation transfer may be computed successfully. For the case where both the donor and acceptor occupy equatorial positions on a rigid cyclohexane bridge, we find beta(calc) = 2 8 per C C bond, compared with the experimental value beta(exp) = 2.6. This work highlights the power of using localized diabatization methods as a tool for modeling nonequilibrium processes