So far, we have used and as bulk isotropic properties of the solid, but it is important to remember the local scale on which each ion jump occurs. Consequently, there are local activation barriers for each possible jump from a given Ag + site, and each Ag + site can have its own vibrational spectrum. Here, we examine one exemplary Ag + jump from both a static (bond valence sum analysis) and lattice dynamical view-point (see Supplemental Note 7 for further discussion). The bond valence sum analysis reveals the potential energy landscape of an ionic jump between two tetrahedrally coordinated Ag3 equilibrium sites (Figure ). The Ag + ion has to jump through the face of the tetrahedron (local potential energy maximum) to a tetrahedrally coordinated interstitial site (local potential energy minimum) from which it can jump to either adjacent Ag + site. The local activation barrier for this jump is expected to be small, since only minor coordination changes (from 4 -3 -4) are necessary and the interstitial site is energetically stablilized. From a lattice dynamics perspective, it is possible to reduce the partial Ag + vibrational density of states (blue shading in Typically, changes in the activation barrier and magnitude of ionic conductivity are discussed from the static perspective, e.g., electronegativity, unit cell and pathway volumes. The sitespecific and directional analysis of phonon modes proposed here allows for identification of prominent vibrational frequencies of the mobile ion from lattice dynamics calculations. The importance of tracking specific vibrational modes within molecular dynamics simulations was recently discussed by Gordiz et al. They showed that the vibrational contributions to ionic conduction are heavily frequency-dependent. Herein, we also assess the relevance and vibrational character (phonon-gas-like or diffuson-like) of phonon modes for thermal transport.