LuBH4 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 12-coordinate geometry to two equivalent H(1), two equivalent H(2), four equivalent H(3), and four equivalent H(4) atoms. In the second Lu site, Lu(2) is bonded to one H(4), two equivalent H(1), two equivalent H(2), three equivalent H(5), and four equivalent H(3) atoms to form LuH12 cuboctahedra that share edges with seven equivalent Lu(2)H12 cuboctahedra, edges with two equivalent B(1)H4 tetrahedra, and edges with four equivalent B(2)H4 tetrahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded to two equivalent H(1) and two equivalent H(2) atoms to form BH4 tetrahedra that share edges with four equivalent Lu(2)H12 cuboctahedra. In the second B site, B(2) is bonded to one H(4), one H(5), and two equivalent H(3) atoms to form BH4 tetrahedra that share edges with four equivalent Lu(2)H12 cuboctahedra. There are five inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(1) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(2) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one Lu(2), two equivalent Lu(1), and one B(2) atom. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to three equivalent Lu(2) and one B(2) atom.
LuBH4 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 12-coordinate geometry to two equivalent H(1), two equivalent H(2), four equivalent H(3), and four equivalent H(4) atoms. Both Lu(1)-H(1) bond lengths are 2.25 Å. Both Lu(1)-H(2) bond lengths are 2.30 Å. All Lu(1)-H(3) bond lengths are 2.26 Å. All Lu(1)-H(4) bond lengths are 2.31 Å. In the second Lu site, Lu(2) is bonded to one H(4), two equivalent H(1), two equivalent H(2), three equivalent H(5), and four equivalent H(3) atoms to form LuH12 cuboctahedra that share edges with seven equivalent Lu(2)H12 cuboctahedra, edges with two equivalent B(1)H4 tetrahedra, and edges with four equivalent B(2)H4 tetrahedra. The Lu(2)-H(4) bond length is 2.22 Å. Both Lu(2)-H(1) bond lengths are 2.27 Å. Both Lu(2)-H(2) bond lengths are 2.26 Å. There are two shorter (2.27 Å) and one longer (2.40 Å) Lu(2)-H(5) bond length. There are two shorter (2.29 Å) and two longer (2.35 Å) Lu(2)-H(3) bond lengths. There are two inequivalent B sites. In the first B site, B(1) is bonded to two equivalent H(1) and two equivalent H(2) atoms to form BH4 tetrahedra that share edges with four equivalent Lu(2)H12 cuboctahedra. Both B(1)-H(1) bond lengths are 1.32 Å. Both B(1)-H(2) bond lengths are 1.29 Å. In the second B site, B(2) is bonded to one H(4), one H(5), and two equivalent H(3) atoms to form BH4 tetrahedra that share edges with four equivalent Lu(2)H12 cuboctahedra. The B(2)-H(4) bond length is 1.28 Å. The B(2)-H(5) bond length is 1.28 Å. Both B(2)-H(3) bond lengths are 1.27 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(1) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(1) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one Lu(1), two equivalent Lu(2), and one B(2) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one Lu(2), two equivalent Lu(1), and one B(2) atom. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to three equivalent Lu(2) and one B(2) atom.