To develop solid electrolytes with high ionic conductivities it is necessary to understand how the chemistry of the host framework modulates the structure and dynamics of the mobile ion species . In many families of solid electrolytes, introducing compositional or structural disorder within the host framework is an effective strategy for increasing ionic conductivity . (M, Sn)F 2 fluorites have previously been proposed to exhibit two distinct forms of hostframework disorder : cation-site-occupation disorder, where the two cationic species are distributed randomly over the available sites; and Sn-lone-pair orientational disorder, where Sn exhibits stereoactive lone pairs with random orientations. This proposed coexistence of two distinct forms of host-framework disorder makes (M, Sn)F 2 fluorites a particularly focus of study in the context of understanding the possible interplay between disorder types, and how, together, they modulate ion transport.