THz) coincides with the maximum of the partial Ag + density of states, which consists of modes that contribute to large thermal displacements. The fact that these average frequencies all reside between 1 and 3 THz where Ag + makes up ~70% of the vibrational density of states, and that Ag + vibrations have been shown to be largely diffuson-like in nature means that diffusons are foundational to understanding both thermal and ionic transport in these materials.