However, density functional theory-based calculations by Chen et al., on tantalum doped systems (Tadoped LLZO) and Li positioning changes in the phase transition, determined the thermodynamic stability of the tetragonal 16f site 'blocked' the formation of cubic LLZO at lower temperatures. Ta 5+ doping was predicted to give octahedral site Li-ion vacancies which weakened the 'blocking' effect of the tetragonal (16f) sites, allowing for lithium-ion redistribution and thus, lowering the transition temperature . These data indicate B site substitution could play an important role in the transition temperature, and that the direct relation to cell volume is perhaps too simplistic. Outside of these reports, work on the tetragonal to cubic phase transition is somewhat limited.