for X=Cl and Br*

Li₂OHCl, Li₂OHBr, and Li₂(OH)_0.9F_0.1Cl have recently been experimentally studied.^2,3,4 All three of these materials have a disordered cubic phase which has high ionic conductivity of possible interest for battery technology. First principles simulations of these materials also identify low temperature ordered phases⁵ which are seen experimentally in only some of the materials. In this presentation, we report the results of our analysis of the material specific contributions of the internal energies as well as the configurational and phonon entropies that effect order-disorder phase transitions in these materials.

² Hood et al. JACS 138, 1768-1771 (2016).
³ Schwering et al. CHEMPHYCHEM 4, 343-348 (2003).
⁴ Li et al. Angew. Chem. Int. Ed. 55 9965-9968 (2016).
⁵ Howard et al. Manuscript submitted to PR Materials (2017).