It should be noted that phonon anharmonicity was not explicitly considered, although anharmonicity is inherently captured in the AIMD simulations used to determine 𝜔 ̅. It should also be mentioned that additional vibrational considerations of the activation barrier may be required when there are, in fact, large changes to the zero-point vibrational energy like in the case of proton conductors. It has also been proposed that proton transport may be described by a polaron-like mechanism, which suggests that the vibrations of the host lattice are also important. Here, only the vibrations of the Li + ions were considered to be relevant for overcoming the activation barrier, as is expected for heavier ion conductors (e.g., Li + , Na + , and Ag ). The vibrations of the host lattice are, however, likely to play a role in the magnitude of 𝐸 A , as they can affect the time-averaged energetic barrier that the mobile ions must overcome.