What Is The Crystal Structure Of Libh4?

The crystal structure of LiBH4 is a tetragonal system with space group P4/nmm. The unit cell contains four formula units of LiBH4, and the lattice parameters are a = b = 4.886 Å, and c = 3.525 Å. The Li+ ions occupy the 2a Wyckoff position (0, 0, 0), while the BH4- ions occupy the 4d Wyckoff position (0.25, 0.25, z). The BH4- ions are orientationally disordered, with their molecular plane randomly oriented along one of the four equivalent <100> directions, resulting in a dynamic disorder. The hydrogen atoms in the BH4- ion are also disordered due to the tunnelling effect.