We present new models and simulations of electron transfer (ET) at the semiconductor-liquid interface (SLI). The simulations are of a "first principles" molecular dynamics type and therefore incorporate electronic structure calculations. An In(H2O)(6)(2+/3+) redox species, water, and InP semiconductor system are focused on. We discuss the problem of electron localization at this interface, especially as it relates to ET. The study allows the mechanism of the ET process to be analyzed. Rate constant calculations are performed with the dynamics of the entire system incorporated. We apparently present the first calculation of electron transfer coupling matrix elements for the SLI.