LaNi5H7 crystallizes in the monoclinic Cc space group. La(1) is bonded to two equivalent H(1), two equivalent H(2), two equivalent H(3), two equivalent H(5), two equivalent H(6), and two equivalent H(7) atoms to form LaH12 cuboctahedra that share corners with six equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, edges with two equivalent Ni(1)H4 tetrahedra, edges with two equivalent Ni(2)H4 tetrahedra, edges with two equivalent Ni(3)H4 tetrahedra, edges with three equivalent Ni(4)H4 tetrahedra, and faces with two equivalent La(1)H12 cuboctahedra. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one H(1), one H(4), one H(6), and one H(7) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. In the second Ni site, Ni(2) is bonded to one H(2), one H(4), one H(5), and one H(7) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. In the third Ni site, Ni(3) is bonded to one H(3), one H(4), one H(5), and one H(6) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one H(1), one H(2), one H(3), and one H(4) atom to form NiH4 tetrahedra that share corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, and edges with three equivalent La(1)H12 cuboctahedra. In the fifth Ni site, Ni(5) is bonded in a trigonal non-coplanar geometry to one H(1), one H(2), and one H(3) atom. There are seven inequivalent H sites. In the first H site, H(5) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(2), and one Ni(3) atom. In the second H site, H(6) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(1), and one Ni(3) atom. In the third H site, H(7) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(1), and one Ni(2) atom. In the fourth H site, H(1) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(1), one Ni(4), and one Ni(5) atom. In the fifth H site, H(2) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(2), one Ni(4), and one Ni(5) atom. In the sixth H site, H(3) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(3), one Ni(4), and one Ni(5) atom. In the seventh H site, H(4) is bonded in a tetrahedral geometry to one Ni(1), one Ni(2), one Ni(3), and one Ni(4) atom.
LaNi5H7 crystallizes in the monoclinic Cc space group. La(1) is bonded to two equivalent H(1), two equivalent H(2), two equivalent H(3), two equivalent H(5), two equivalent H(6), and two equivalent H(7) atoms to form LaH12 cuboctahedra that share corners with six equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, edges with two equivalent Ni(1)H4 tetrahedra, edges with two equivalent Ni(2)H4 tetrahedra, edges with two equivalent Ni(3)H4 tetrahedra, edges with three equivalent Ni(4)H4 tetrahedra, and faces with two equivalent La(1)H12 cuboctahedra. There is one shorter (2.66 Å) and one longer (2.75 Å) La(1)-H(1) bond length. There is one shorter (2.66 Å) and one longer (2.75 Å) La(1)-H(2) bond length. There is one shorter (2.66 Å) and one longer (2.76 Å) La(1)-H(3) bond length. There is one shorter (2.57 Å) and one longer (2.70 Å) La(1)-H(5) bond length. There is one shorter (2.57 Å) and one longer (2.70 Å) La(1)-H(6) bond length. There is one shorter (2.57 Å) and one longer (2.70 Å) La(1)-H(7) bond length. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one H(1), one H(4), one H(6), and one H(7) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. The Ni(1)-H(1) bond length is 1.65 Å. The Ni(1)-H(4) bond length is 1.65 Å. The Ni(1)-H(6) bond length is 1.61 Å. The Ni(1)-H(7) bond length is 1.61 Å. In the second Ni site, Ni(2) is bonded to one H(2), one H(4), one H(5), and one H(7) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. The Ni(2)-H(2) bond length is 1.65 Å. The Ni(2)-H(4) bond length is 1.65 Å. The Ni(2)-H(5) bond length is 1.61 Å. The Ni(2)-H(7) bond length is 1.61 Å. In the third Ni site, Ni(3) is bonded to one H(3), one H(4), one H(5), and one H(6) atom to form NiH4 tetrahedra that share corners with two equivalent La(1)H12 cuboctahedra, corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(4)H4 tetrahedra, and edges with two equivalent La(1)H12 cuboctahedra. The Ni(3)-H(3) bond length is 1.65 Å. The Ni(3)-H(4) bond length is 1.65 Å. The Ni(3)-H(5) bond length is 1.61 Å. The Ni(3)-H(6) bond length is 1.61 Å. In the fourth Ni site, Ni(4) is bonded to one H(1), one H(2), one H(3), and one H(4) atom to form NiH4 tetrahedra that share corners with two equivalent Ni(1)H4 tetrahedra, corners with two equivalent Ni(2)H4 tetrahedra, corners with two equivalent Ni(3)H4 tetrahedra, and edges with three equivalent La(1)H12 cuboctahedra. The Ni(4)-H(1) bond length is 1.67 Å. The Ni(4)-H(2) bond length is 1.67 Å. The Ni(4)-H(3) bond length is 1.67 Å. The Ni(4)-H(4) bond length is 1.62 Å. In the fifth Ni site, Ni(5) is bonded in a trigonal non-coplanar geometry to one H(1), one H(2), and one H(3) atom. The Ni(5)-H(1) bond length is 1.65 Å. The Ni(5)-H(2) bond length is 1.65 Å. The Ni(5)-H(3) bond length is 1.64 Å. There are seven inequivalent H sites. In the first H site, H(5) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(2), and one Ni(3) atom. In the second H site, H(6) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(1), and one Ni(3) atom. In the third H site, H(7) is bonded in a distorted bent 120 degrees geometry to two equivalent La(1), one Ni(1), and one Ni(2) atom. In the fourth H site, H(1) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(1), one Ni(4), and one Ni(5) atom. In the fifth H site, H(2) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(2), one Ni(4), and one Ni(5) atom. In the sixth H site, H(3) is bonded in a 3-coordinate geometry to two equivalent La(1), one Ni(3), one Ni(4), and one Ni(5) atom. In the seventh H site, H(4) is bonded in a tetrahedral geometry to one Ni(1), one Ni(2), one Ni(3), and one Ni(4) atom.