CaMg6Ce is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Mg(2); four Mg(1,1); four Mg(3,3); and two equivalent Ce(1) atoms to form CaCe2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with six equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Mg(4)Ce2Mg10 cuboctahedra. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with ten Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Ca(1); two equivalent Mg(4); four Mg(1,1); and four Mg(3,3) atoms to form MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with six equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Ce(1)Ca2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra. In the fourth Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra. In the fifth Mg site, Mg(4) is bonded to two equivalent Mg(2); four Mg(1,1); four Mg(3,3,3); and two equivalent Ce(1) atoms to form MgCe2Mg10 cuboctahedra that share corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Ca(1)Ce2Mg10 cuboctahedra. In the sixth Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with ten Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(3,3)Ca2Ce2Mg8 cuboctahedra. In the seventh Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra. Ce(1) is bonded to two equivalent Ca(1); two equivalent Mg(4); four equivalent Mg(1); and four Mg(3,3,3) atoms to form CeCa2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with six equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Mg(2)Ca2Mg10 cuboctahedra.
CaMg6Ce is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Mg(2); four Mg(1,1); four Mg(3,3); and two equivalent Ce(1) atoms to form CaCe2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with six equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Mg(4)Ce2Mg10 cuboctahedra. Both Ca(1)-Mg(2) bond lengths are 3.40 Å. There are two shorter (3.20 Å) and two longer (3.37 Å) Ca(1)-Mg(1,1) bond lengths. All Ca(1)-Mg(3,3) bond lengths are 3.27 Å. Both Ca(1)-Ce(1) bond lengths are 3.41 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with ten Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra. There is one shorter (3.39 Å) and one longer (3.41 Å) Mg(1)-Mg(1) bond length. There is one shorter (3.27 Å) and one longer (3.30 Å) Mg(1)-Mg(2) bond length. Both Mg(1)-Mg(3) bond lengths are 3.26 Å. Both Mg(1)-Mg(4) bond lengths are 3.27 Å. Both Mg(1)-Ce(1) bond lengths are 3.26 Å. In the second Mg site, Mg(2) is bonded to two equivalent Ca(1); two equivalent Mg(4); four Mg(1,1); and four Mg(3,3) atoms to form MgCa2Mg10 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with six equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Ce(1)Ca2Mg10 cuboctahedra. Both Mg(2)-Mg(4) bond lengths are 3.32 Å. The Mg(2)-Mg(1) bond length is 3.30 Å. All Mg(2)-Mg(3,3) bond lengths are 3.29 Å. In the third Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra. Both Mg(3)-Ca(1) bond lengths are 3.27 Å. There is one shorter (3.39 Å) and one longer (3.40 Å) Mg(3)-Mg(3) bond length. There is one shorter (3.21 Å) and one longer (3.36 Å) Mg(3)-Mg(4) bond length. There is one shorter (3.17 Å) and one longer (3.41 Å) Mg(3)-Ce(1) bond length. In the fourth Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra. Both Mg(3)-Mg(1) bond lengths are 3.26 Å. There is one shorter (3.21 Å) and one longer (3.36 Å) Mg(3)-Mg(4) bond length. There is one shorter (3.17 Å) and one longer (3.41 Å) Mg(3)-Ce(1) bond length. In the fifth Mg site, Mg(4) is bonded to two equivalent Mg(2); four Mg(1,1); four Mg(3,3,3); and two equivalent Ce(1) atoms to form MgCe2Mg10 cuboctahedra that share corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Ca(1)Ce2Mg10 cuboctahedra. Both Mg(4)-Mg(1) bond lengths are 3.27 Å. The Mg(4)-Mg(3) bond length is 3.21 Å. Both Mg(4)-Ce(1) bond lengths are 3.40 Å. In the sixth Mg site, Mg(1) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(2)Ca2Mg10 cuboctahedra; corners with ten Mg(1,1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(1,1)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(3,3)Ca2Ce2Mg8 cuboctahedra. There is one shorter (3.39 Å) and one longer (3.41 Å) Mg(1)-Mg(1) bond length. Both Mg(1)-Mg(3) bond lengths are 3.26 Å. Both Mg(1)-Ce(1) bond lengths are 3.26 Å. In the seventh Mg site, Mg(3) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with ten Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(2)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3)Ca2Ce2Mg8 cuboctahedra; and faces with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra. Both Mg(3)-Mg(1) bond lengths are 3.26 Å. Both Mg(3)-Mg(2) bond lengths are 3.29 Å. There is one shorter (3.39 Å) and one longer (3.40 Å) Mg(3)-Mg(3) bond length. There is one shorter (3.17 Å) and one longer (3.41 Å) Mg(3)-Ce(1) bond length. Ce(1) is bonded to two equivalent Ca(1); two equivalent Mg(4); four equivalent Mg(1); and four Mg(3,3,3) atoms to form CeCa2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Ce2Mg10 cuboctahedra; corners with six equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(4)Ce2Mg10 cuboctahedra; edges with four equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with eight Mg(1,1)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(4)Ce2Mg10 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four equivalent Mg(1)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; and faces with six equivalent Mg(2)Ca2Mg10 cuboctahedra.