On the structure of lithium peroxide, Li2O2.

The two published lithium peroxide structures, both ascribed to the hexagonal P6 space group, were subjected to reinterpretation, and another more symmetric structure, now belonging to the P6(3)/mmc space group, was found. Detailed density-functional quantum mechanical calculations and crystal structure optimizations were carried out on both structures and the energetic arguments obtained therewith helped to rule out one of them.