Co3H is H-Phase-derived structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 3-coordinate geometry to three equivalent Co(2) and three equivalent H(1) atoms. In the second Co site, Co(2) is bonded to six equivalent Co(1) and six equivalent Co(2) atoms to form CoCo12 cuboctahedra that share corners with six equivalent Co(2)Co12 cuboctahedra, corners with six equivalent H(1)Co6 octahedra, edges with six equivalent Co(2)Co12 cuboctahedra, edges with six equivalent H(1)Co6 octahedra, and faces with six equivalent Co(2)Co12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. H(1) is bonded to six equivalent Co(1) atoms to form HCo6 octahedra that share corners with six equivalent Co(2)Co12 cuboctahedra, edges with six equivalent Co(2)Co12 cuboctahedra, and edges with six equivalent H(1)Co6 octahedra.
Co3H is H-Phase-derived structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 3-coordinate geometry to three equivalent Co(2) and three equivalent H(1) atoms. All Co(1)-Co(2) bond lengths are 2.43 Å. All Co(1)-H(1) bond lengths are 1.81 Å. In the second Co site, Co(2) is bonded to six equivalent Co(1) and six equivalent Co(2) atoms to form CoCo12 cuboctahedra that share corners with six equivalent Co(2)Co12 cuboctahedra, corners with six equivalent H(1)Co6 octahedra, edges with six equivalent Co(2)Co12 cuboctahedra, edges with six equivalent H(1)Co6 octahedra, and faces with six equivalent Co(2)Co12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. All Co(2)-Co(2) bond lengths are 2.52 Å. H(1) is bonded to six equivalent Co(1) atoms to form HCo6 octahedra that share corners with six equivalent Co(2)Co12 cuboctahedra, edges with six equivalent Co(2)Co12 cuboctahedra, and edges with six equivalent H(1)Co6 octahedra.