Ca2Ni10H crystallizes in the trigonal P3m1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent Ni(6) atoms. In the second Ca site, Ca(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(3), and six equivalent Ni(6) atoms. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a single-bond geometry to three equivalent Ca(1), three equivalent Ni(6), and one H(1) atom. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ni(3), and three equivalent Ni(6) atoms. In the third Ni site, Ni(3) is bonded in a single-bond geometry to two equivalent Ca(1), two equivalent Ca(2), one Ni(2), one Ni(4), one Ni(5), and one H(1) atom. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ni(3), and three equivalent Ni(6) atoms. In the fifth Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ni(3), and three equivalent Ni(6) atoms. In the sixth Ni site, Ni(6) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Ni(1), one Ni(2), one Ni(4), one Ni(5), and four equivalent Ni(6) atoms to form NiCa4Ni8 cuboctahedra that share corners with four equivalent Ni(6)Ca4Ni8 cuboctahedra,  a cornercorner with one H(1)Ni4 tetrahedra, edges with two equivalent Ni(6)Ca4Ni8 cuboctahedra, and faces with eight equivalent Ni(6)Ca4Ni8 cuboctahedra. H(1) is bonded to one Ni(1) and three equivalent Ni(3) atoms to form HNi4 tetrahedra that share corners with three equivalent Ni(6)Ca4Ni8 cuboctahedra.
Ca2Ni10H crystallizes in the trigonal P3m1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 18-coordinate geometry to three equivalent Ni(1), three equivalent Ni(2), six equivalent Ni(3), and six equivalent Ni(6) atoms. All Ca(1)-Ni(1) bond lengths are 2.88 Å. All Ca(1)-Ni(2) bond lengths are 2.88 Å. All Ca(1)-Ni(3) bond lengths are 3.20 Å. All Ca(1)-Ni(6) bond lengths are 3.19 Å. In the second Ca site, Ca(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(3), and six equivalent Ni(6) atoms. All Ca(2)-Ni(4) bond lengths are 2.88 Å. All Ca(2)-Ni(5) bond lengths are 2.88 Å. All Ca(2)-Ni(3) bond lengths are 3.17 Å. All Ca(2)-Ni(6) bond lengths are 3.16 Å. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a single-bond geometry to three equivalent Ca(1), three equivalent Ni(6), and one H(1) atom. All Ni(1)-Ni(6) bond lengths are 2.39 Å. The Ni(1)-H(1) bond length is 1.60 Å. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Ca(1), three equivalent Ni(3), and three equivalent Ni(6) atoms. All Ni(2)-Ni(3) bond lengths are 2.46 Å. All Ni(2)-Ni(6) bond lengths are 2.43 Å. In the third Ni site, Ni(3) is bonded in a single-bond geometry to two equivalent Ca(1), two equivalent Ca(2), one Ni(2), one Ni(4), one Ni(5), and one H(1) atom. The Ni(3)-Ni(4) bond length is 2.46 Å. The Ni(3)-Ni(5) bond length is 2.40 Å. The Ni(3)-H(1) bond length is 1.58 Å. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ni(3), and three equivalent Ni(6) atoms. All Ni(4)-Ni(6) bond lengths are 2.43 Å. In the fifth Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Ca(2), three equivalent Ni(3), and three equivalent Ni(6) atoms. All Ni(5)-Ni(6) bond lengths are 2.40 Å. In the sixth Ni site, Ni(6) is bonded to two equivalent Ca(1), two equivalent Ca(2), one Ni(1), one Ni(2), one Ni(4), one Ni(5), and four equivalent Ni(6) atoms to form NiCa4Ni8 cuboctahedra that share corners with four equivalent Ni(6)Ca4Ni8 cuboctahedra,  a cornercorner with one H(1)Ni4 tetrahedra, edges with two equivalent Ni(6)Ca4Ni8 cuboctahedra, and faces with eight equivalent Ni(6)Ca4Ni8 cuboctahedra. There are two shorter (2.48 Å) and two longer (2.51 Å) Ni(6)-Ni(6) bond lengths. H(1) is bonded to one Ni(1) and three equivalent Ni(3) atoms to form HNi4 tetrahedra that share corners with three equivalent Ni(6)Ca4Ni8 cuboctahedra.