CsMg14Hf crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Hf(1) atoms to form CsHf2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra, faces with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, and faces with six equivalent Mg(7)HfMg11 cuboctahedra. 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 four equivalent Hf(1)Cs2Mg10 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(7)HfMg11 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 four equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)CsMg11 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Cs(1), two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and two equivalent Hf(1) atoms to form distorted MgCs2Hf2Mg8 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with six equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra. 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 four equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, corners with four equivalent Hf(1)Cs2Mg10 cuboctahedra, 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)CsMg11 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 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 1-coordinate geometry to one Cs(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(6), two equivalent Mg(7), and one Hf(1) atom. In the sixth Mg site, Mg(6) is bonded to one Cs(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 MgCsMg11 cuboctahedra that share corners with four equivalent Mg(7)HfMg11 cuboctahedra, corners with six equivalent Mg(6)CsMg11 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with two equivalent Mg(7)HfMg11 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Cs(1)Hf2Mg10 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(2)Mg12 cuboctahedra, and faces with three equivalent Hf(1)Cs2Mg10 cuboctahedra. In the seventh Mg site, Mg(7) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one Hf(1) atom to form MgHfMg11 cuboctahedra that share corners with four equivalent Mg(6)CsMg11 cuboctahedra, corners with six equivalent Mg(7)HfMg11 cuboctahedra, edges with two equivalent Mg(6)CsMg11 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one Hf(1)Cs2Mg10 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Cs(1)Hf2Mg10 cuboctahedra, and faces with three equivalent Mg(1)Mg12 cuboctahedra. Hf(1) is bonded to two equivalent Cs(1), two equivalent Mg(7), four equivalent Mg(3), and four equivalent Mg(5) atoms to form distorted HfCs2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Hf(1)Cs2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, and faces with six equivalent Mg(6)CsMg11 cuboctahedra.
CsMg14Hf crystallizes in the orthorhombic Amm2 space group. Cs(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Hf(1) atoms to form CsHf2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra, faces with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, and faces with six equivalent Mg(7)HfMg11 cuboctahedra. Both Cs(1)-Mg(6) bond lengths are 3.44 Å. There are two shorter (3.28 Å) and two longer (3.29 Å) Cs(1)-Mg(3) bond lengths. All Cs(1)-Mg(5) bond lengths are 3.42 Å. Both Cs(1)-Hf(1) bond lengths are 3.36 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 four equivalent Hf(1)Cs2Mg10 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(7)HfMg11 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.36 Å. Both Mg(1)-Mg(6) bond lengths are 3.16 Å. There are two shorter (3.26 Å) and two longer (3.31 Å) Mg(1)-Mg(4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.22 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 four equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with six equivalent Mg(6)CsMg11 cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.26 Å. There are two shorter (3.25 Å) and two longer (3.32 Å) Mg(2)-Mg(4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.11 Å. In the third Mg site, Mg(3) is bonded to two equivalent Cs(1), two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and two equivalent Hf(1) atoms to form distorted MgCs2Hf2Mg8 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with four equivalent Mg(4)Mg12 cuboctahedra, corners with six equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(6)CsMg11 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, and faces with two equivalent Hf(1)Cs2Mg10 cuboctahedra. There is one shorter (3.34 Å) and one longer (3.37 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5) bond lengths are 3.33 Å. Both Mg(3)-Mg(6) bond lengths are 3.38 Å. Both Mg(3)-Mg(7) bond lengths are 3.21 Å. There is one shorter (3.17 Å) and one longer (3.40 Å) Mg(3)-Hf(1) bond length. 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 four equivalent Cs(1)Hf2Mg10 cuboctahedra, corners with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, corners with four equivalent Hf(1)Cs2Mg10 cuboctahedra, 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)CsMg11 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 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 (3.29 Å) and one longer (3.42 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.14 Å. Both Mg(4)-Mg(6) bond lengths are 3.10 Å. Both Mg(4)-Mg(7) bond lengths are 3.30 Å. In the fifth Mg site, Mg(5) is bonded in a 1-coordinate geometry to one Cs(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(6), two equivalent Mg(7), and one Hf(1) atom. There is one shorter (3.14 Å) and one longer (3.44 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.22 Å) and one longer (3.37 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Hf(1) bond length is 3.27 Å. In the sixth Mg site, Mg(6) is bonded to one Cs(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 MgCsMg11 cuboctahedra that share corners with four equivalent Mg(7)HfMg11 cuboctahedra, corners with six equivalent Mg(6)CsMg11 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with two equivalent Mg(7)HfMg11 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Cs(1)Hf2Mg10 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Mg(2)Mg12 cuboctahedra, and faces with three equivalent Hf(1)Cs2Mg10 cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.37 Å. In the seventh Mg site, Mg(7) is bonded to one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), four equivalent Mg(5), and one Hf(1) atom to form MgHfMg11 cuboctahedra that share corners with four equivalent Mg(6)CsMg11 cuboctahedra, corners with six equivalent Mg(7)HfMg11 cuboctahedra, edges with two equivalent Mg(6)CsMg11 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with two equivalent Hf(1)Cs2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one Hf(1)Cs2Mg10 cuboctahedra, faces with two equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, faces with two equivalent Mg(6)CsMg11 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with three equivalent Cs(1)Hf2Mg10 cuboctahedra, and faces with three equivalent Mg(1)Mg12 cuboctahedra. The Mg(7)-Hf(1) bond length is 3.25 Å. Hf(1) is bonded to two equivalent Cs(1), two equivalent Mg(7), four equivalent Mg(3), and four equivalent Mg(5) atoms to form distorted HfCs2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Hf(1)Cs2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Cs(1)Hf2Mg10 cuboctahedra, edges with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, edges with four equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Cs(1)Hf2Mg10 cuboctahedra, faces with two equivalent Mg(7)HfMg11 cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with four equivalent Mg(3)Cs2Hf2Mg8 cuboctahedra, and faces with six equivalent Mg(6)CsMg11 cuboctahedra.