On the crystal structure of lithium peroxide, Li2O2

The two published lithium peroxide structures, both ascribed to the hexagonal P -6 space group, were subjected to reinterpretation and another more symmetric structure, now belonging to the P 63/m m c space group, was found. Detailed density-functional quantum mechanical calculations and crystal structure optimisations were carried out on both structures and the energetic arguments obtained therewith helped to rule out one of them.