Lithium Subhydrides Under Pressure and their Superatom-Like Building   Blocks
  Evolutionary structure searches are used to predict a new class of compounds in the lithium--rich region of the lithium/hydrogen phase diagram under pressure. First principles computations show that LimH, 4<m<9, are stabilized with respect to LiH and Li between 50-100 GPa. The building block of all of the lithium subhydrides is an Li8H cluster, which can be thought of as a superalkali. The geometries and electronic structures of these phases is analogous to that of the well-known alkali metal suboxides. 
James Hooper and Eva Zurek
cond-mat.mtrl-sci