We discuss the rich vibrational dynamics of nanometer-scale semiconductingand insulating crystals as probed by localized electronic impurity states, withan emphasis on nanoparticles that are only weakly coupled to their environment.Two principal regimes of electron-phonon dynamics are distinguished, and abrief survey of vibrational-mode broadening mechanisms is presented. Recentwork on the effects of mechanical interaction with the environment isdiscussed.
