Table . Dielectric constants calculated using a variety of methods; * denotes calculations from this work; DFPT (density functional perturbation theory) or FD (finite differences method) calculations were used to determine the low-frequency, 𝜖 ionic , response, while IP-RPA (independent particle random phase approximation) optical calculations were used to determine the high-frequency, 𝜖 ∞ , response. Further details can be found in the methodology section.