LiMg14B crystallizes in the orthorhombic Amm2 space group. Li(1) is bonded in a 10-coordinate geometry to two equivalent Mg(6), four equivalent Mg(3), and four equivalent Mg(5) atoms. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)LiMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)LiMg11 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Li(1), two equivalent Mg(6), two equivalent Mg(7), and one B(1) atom. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, and faces with two equivalent Mg(4)Mg12 cuboctahedra. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to one Li(1), one Mg(1), one Mg(2), one Mg(4), two equivalent Mg(6), two equivalent Mg(7), and one B(1) atom. In the sixth Mg site, Mg(6) is bonded to one Li(1), one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), and four equivalent Mg(5) atoms to form distorted MgLiMg11 cuboctahedra that share corners with six equivalent Mg(6)LiMg11 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with three equivalent Mg(2)Mg12 cuboctahedra. In the seventh Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one B(1) atom. B(1) is bonded in a 8-coordinate geometry to two equivalent Mg(3), two equivalent Mg(7), and four equivalent Mg(5) atoms.
LiMg14B crystallizes in the orthorhombic Amm2 space group. Li(1) is bonded in a 10-coordinate geometry to two equivalent Mg(6), four equivalent Mg(3), and four equivalent Mg(5) atoms. Both Li(1)-Mg(6) bond lengths are 3.17 Å. There are two shorter (2.89 Å) and two longer (3.35 Å) Li(1)-Mg(3) bond lengths. All Li(1)-Mg(5) bond lengths are 2.83 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)LiMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, and faces with four equivalent Mg(4)Mg12 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.16 Å. Both Mg(1)-Mg(6) bond lengths are 3.07 Å. There are two shorter (3.05 Å) and two longer (3.18 Å) Mg(1)-Mg(4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.36 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)LiMg11 cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.14 Å. There are two shorter (3.09 Å) and two longer (3.15 Å) Mg(2)-Mg(4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.30 Å. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Li(1), two equivalent Mg(6), two equivalent Mg(7), and one B(1) atom. Both Mg(3)-Mg(6) bond lengths are 3.06 Å. Both Mg(3)-Mg(7) bond lengths are 2.95 Å. The Mg(3)-B(1) bond length is 2.61 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, and faces with two equivalent Mg(4)Mg12 cuboctahedra. There is one shorter (3.13 Å) and one longer (3.18 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.38 Å. Both Mg(4)-Mg(6) bond lengths are 3.06 Å. Both Mg(4)-Mg(7) bond lengths are 3.13 Å. In the fifth Mg site, Mg(5) is bonded in a 2-coordinate geometry to one Li(1), one Mg(1), one Mg(2), one Mg(4), two equivalent Mg(6), two equivalent Mg(7), and one B(1) atom. There is one shorter (3.12 Å) and one longer (3.17 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.03 Å) and one longer (3.23 Å) Mg(5)-Mg(7) bond length. The Mg(5)-B(1) bond length is 2.85 Å. In the sixth Mg site, Mg(6) is bonded to one Li(1), one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), and four equivalent Mg(5) atoms to form distorted MgLiMg11 cuboctahedra that share corners with six equivalent Mg(6)LiMg11 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(6)LiMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with three equivalent Mg(2)Mg12 cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.16 Å. In the seventh Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one B(1) atom. The Mg(7)-B(1) bond length is 2.90 Å. B(1) is bonded in a 8-coordinate geometry to two equivalent Mg(3), two equivalent Mg(7), and four equivalent Mg(5) atoms.