The coupling of phonons to electrons, excitons and other phonons plays a defining role in material properties, including charge and energy transport, light emission, and superconductivity. In atomic solids such as Si or GaAs, phonons are delocalized over the three-dimensional (3D) lattice and are determined by bonding and crystal symmetry. In molecular materials, by contrast, localized molecular vibrations couple to electrons to produce, for example, high temperature superconductivity, as in A3C60.