115In and 19F MAS NMR study of (NH4)3InF6 phases

► Solid state NMR was applied to study the room and high temperature phases of (NH4)3InF6 using 19F and 115In as probe nuclei. ► For the first time static 115In spectra of (NH4)3InF6 were taken at three different fields at room temperature. ► The occurrence of two different In sites agrees with the occurrence of the different phases, namely the tetragonal and the monoclinic ones. ► The scalar In-F coupling, rarely observed in solid state NMR, is evidenced in both room and high temperature phases of (NH4)3InF6, and measured in the high temperature phase.