Calculation of an effective three-ionic interactions potential in   metallic hydrogen
  The pair- and three-proton interaction potentials for metal-phase hydrogen are calculated. Irreducible three-proton interactions are shown to be essential in the development of the metal hydrogen structure. Possible manifestations of the three-ion interactions in the structure of quickly quenched metallic systems are discussed. Existence of amorphous metals is related to manifestations of the three-ion interactions in non-equilibrium conditions when amorphisation front travels through a liquid metal. 
E. V. Vasiliu, S. D. Kaim, N. P. Kovalenko