Computational Chemistry-Guided Syntheses and Crystal Structures of the Heavier Lanthanide Hydride Oxides DyHO, ErHO, and LuHO

Heteroanionic hydrides offer great possibilities in the design of functional materials. For ternary rare earth hydride oxide REHO, several modifications were reported with indications for a significant phase width respect to H and O cubic representatives. We obtained DyHO ErHO as well thus far elusive LuHO from solid-state reactions RE2O3 REH3 or LuH3 CaO investigated their crystal structures by neutron X-ray powder diffraction. While DyHO, ErHO, adopted anion-ordered half-Heusler LiAlSi structure type (F4¯3m, a(DyHO) = 5.30945(10) Å, a(ErHO) 5.24615(7) a(LuHO) 5.171591(13) Å), additionally formed orthorhombic anti-LiMgN (Pnma; LuHO: 7.3493(7) b 3.6747(4) c 5.1985(3) Å; LuDO: 7.3116(16) 3.6492(8) 5.2021(7) Å). A comparison compounds’ lattice parameters enabled distinction between REHO REH1+2xO1−x (x < 0 x > 0). Furthermore, computational chemistry study revealed formation compounds smallest elements be disfavored sesquioxides, which is why they may only mild synthesis conditions.