A range of sodalites of general formula LiNa(AlSiO)Cl have been synthesised by structure conversion and ion exchange reactions. High resolution Si NMR spectra of these compounds demonstrate a single resonance, the frequency of which varies smoothly with lithium content and the geometry of the Si-(OAl) tetrahedron determined by powder neutron diffraction. Incorporation of lithium in the sodalite structure results in contraction of the Si-O-Al bond angle to accommodate the preferred coordination geometry of the smaller cavity species. In partially exchanged materials the chloride ion is displaced away from the cavity centre.
Weller, M. T., & Wong, G. (1989). Characterisation of novel sodalites by neutron diffraction and solid-state NMR. Solid State Ionics, 32-33(PART 1), 430-435. https://doi.org/10.1016/0167-2738(89)90251-8