“…Recently, very interesting transformations induced by hydrogen were observed in the cubic C15 (Fd3m space group) Laves phase type compounds of yttrium and rare earths with manganese, namely YMn 2 H x [1], DyMn 2 H x [2], TbMn 2 H x [3] and GdMn 2 H x [4]. Hydrogen atoms are located there in the A2B2 interstitial sites.…”