CaMg14Ce crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Mg(6); four Mg(3,3,3); four Mg(5,5,5,5); and two equivalent Ce(1) atoms to form CaCe2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5,5,5)CaCeMg10 cuboctahedra; and faces with six equivalent Mg(7)CeMg11 cuboctahedra. There are thirteen inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four Mg(5,5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)CeMg11 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(5,5,5)CaCeMg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)CaMg11 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six Mg(4,4)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 Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. In the fifth Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. In the sixth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six Mg(4,4)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(5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. In the seventh Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the eighth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the ninth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the tenth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the eleventh Mg site, Mg(6) is bonded to one Ca(1); one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); and four Mg(5,5,5) atoms to form distorted MgCaMg11 cuboctahedra that share corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with six equivalent Mg(6)CaMg11 cuboctahedra; corners with eight Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(7)CeMg11 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four Mg(5,5,5)CaCeMg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with four Mg(5,5,5)CaCeMg10 cuboctahedra. In the twelfth Mg site, Mg(7) is bonded to one Mg(2); two Mg(3,3); two Mg(4,4); two equivalent Mg(6); four Mg(5,5,5); and one Ce(1) atom to form MgCeMg11 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with six equivalent Mg(7)CeMg11 cuboctahedra; corners with eight Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four Mg(5,5,5)CaCeMg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two Mg(3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with three equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with four Mg(5,5,5)CaCeMg10 cuboctahedra. In the thirteenth Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. Ce(1) is bonded to two equivalent Ca(1); two equivalent Mg(7); four Mg(3,3,3); and four Mg(5,5,5) atoms to form CeCa2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5,5)CaCeMg10 cuboctahedra; and faces with six equivalent Mg(6)CaMg11 cuboctahedra.
CaMg14Ce crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Mg(6); four Mg(3,3,3); four Mg(5,5,5,5); and two equivalent Ce(1) atoms to form CaCe2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5,5,5)CaCeMg10 cuboctahedra; and faces with six equivalent Mg(7)CeMg11 cuboctahedra. Both Ca(1)-Mg(6) bond lengths are 3.25 Å. There are two shorter (3.22 Å) and two longer (3.31 Å) Ca(1)-Mg(3,3,3) bond lengths. All Ca(1)-Mg(5,5,5,5) bond lengths are 3.28 Å. Both Ca(1)-Ce(1) bond lengths are 3.34 Å. There are thirteen inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4); and four Mg(5,5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)CeMg11 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.34 Å. Both Mg(1)-Mg(6) bond lengths are 3.23 Å. There are two shorter (3.26 Å) and two longer (3.27 Å) Mg(1)-Mg(4,4) bond lengths. All Mg(1)-Mg(5,5,5,5) bond lengths are 3.23 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4); and four Mg(5,5,5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; faces with four Mg(5,5,5)CaCeMg10 cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)CaMg11 cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.22 Å. There are two shorter (3.26 Å) and two longer (3.27 Å) Mg(2)-Mg(4,4) bond lengths. All Mg(2)-Mg(5,5,5) bond lengths are 3.21 Å. In the third Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. There is one shorter (3.31 Å) and one longer (3.38 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5,5) bond lengths are 3.24 Å. Both Mg(3)-Mg(6) bond lengths are 3.26 Å. Both Mg(3)-Mg(7) bond lengths are 3.25 Å. There is one shorter (3.23 Å) and one longer (3.30 Å) Mg(3)-Ce(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 Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six Mg(4,4)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 Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. There is one shorter (3.33 Å) and one longer (3.35 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5,5) bond lengths are 3.19 Å. Both Mg(4)-Mg(6) bond lengths are 3.24 Å. Both Mg(4)-Mg(7) bond lengths are 3.25 Å. In the fifth Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four equivalent Mg(5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. Both Mg(3)-Mg(5,5) bond lengths are 3.24 Å. Both Mg(3)-Mg(6) bond lengths are 3.26 Å. Both Mg(3)-Mg(7) bond lengths are 3.25 Å. There is one shorter (3.23 Å) and one longer (3.30 Å) Mg(3)-Ce(1) bond length. In the sixth Mg site, Mg(4) is bonded to two equivalent Mg(1); two equivalent Mg(2); two equivalent Mg(4); two Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Ca(1)Ce2Mg10 cuboctahedra; corners with four equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; corners with four equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with six Mg(4,4)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(5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. Both Mg(4)-Mg(5,5) bond lengths are 3.19 Å. Both Mg(4)-Mg(6) bond lengths are 3.24 Å. Both Mg(4)-Mg(7) bond lengths are 3.25 Å. In the seventh Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. There is one shorter (3.31 Å) and one longer (3.37 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.23 Å) and one longer (3.29 Å) Mg(5)-Mg(6) bond length. Both Mg(5)-Mg(7) bond lengths are 3.26 Å. The Mg(5)-Ce(1) bond length is 3.27 Å. In the eighth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. There is one shorter (3.31 Å) and one longer (3.37 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.23 Å) and one longer (3.29 Å) Mg(5)-Mg(6) bond length. Both Mg(5)-Mg(7) bond lengths are 3.26 Å. The Mg(5)-Ce(1) bond length is 3.27 Å. In the ninth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. The Mg(5)-Mg(2) bond length is 3.21 Å. There is one shorter (3.23 Å) and one longer (3.29 Å) Mg(5)-Mg(6) bond length. Both Mg(5)-Mg(7) bond lengths are 3.26 Å. The Mg(5)-Ce(1) bond length is 3.27 Å. In the tenth Mg site, Mg(5) is bonded to one Ca(1), one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and one Ce(1) atom to form distorted MgCaCeMg10 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with ten Mg(5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Mg(5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(7)CeMg11 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 two equivalent Ce(1)Ca2Mg10 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5)CaCeMg10 cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. There is one shorter (3.23 Å) and one longer (3.29 Å) Mg(5)-Mg(6) bond length. Both Mg(5)-Mg(7) bond lengths are 3.26 Å. The Mg(5)-Ce(1) bond length is 3.27 Å. In the eleventh Mg site, Mg(6) is bonded to one Ca(1); one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); and four Mg(5,5,5) atoms to form distorted MgCaMg11 cuboctahedra that share corners with four equivalent Mg(7)CeMg11 cuboctahedra; corners with six equivalent Mg(6)CaMg11 cuboctahedra; corners with eight Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(7)CeMg11 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four Mg(5,5,5)CaCeMg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Ca(1)Ce2Mg10 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with four Mg(5,5,5)CaCeMg10 cuboctahedra. Both Mg(6)-Mg(3) bond lengths are 3.26 Å. Both Mg(6)-Mg(7) bond lengths are 3.34 Å. In the twelfth Mg site, Mg(7) is bonded to one Mg(2); two Mg(3,3); two Mg(4,4); two equivalent Mg(6); four Mg(5,5,5); and one Ce(1) atom to form MgCeMg11 cuboctahedra that share corners with four equivalent Mg(6)CaMg11 cuboctahedra; corners with six equivalent Mg(7)CeMg11 cuboctahedra; corners with eight Mg(5,5,5)CaCeMg10 cuboctahedra; edges with two equivalent Mg(6)CaMg11 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four Mg(5,5,5)CaCeMg10 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Ce(1)Ca2Mg10 cuboctahedra; faces with two Mg(3,3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with three equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with four Mg(5,5,5)CaCeMg10 cuboctahedra. The Mg(7)-Ce(1) bond length is 3.24 Å. In the thirteenth Mg site, Mg(3) is bonded to two equivalent Ca(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Ce(1) atoms to form distorted MgCa2Ce2Mg8 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 Mg(3,3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; edges with two equivalent Ce(1)Ca2Mg10 cuboctahedra; edges with four Mg(5,5)CaCeMg10 cuboctahedra; edges with four equivalent Mg(6)CaMg11 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(3)Ca2Ce2Mg8 cuboctahedra; faces with two equivalent Mg(6)CaMg11 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Ce(1)Ca2Mg10 cuboctahedra; and faces with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra. There is one shorter (3.31 Å) and one longer (3.38 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5,5) bond lengths are 3.24 Å. Both Mg(3)-Mg(7) bond lengths are 3.25 Å. There is one shorter (3.23 Å) and one longer (3.30 Å) Mg(3)-Ce(1) bond length. Ce(1) is bonded to two equivalent Ca(1); two equivalent Mg(7); four Mg(3,3,3); and four Mg(5,5,5) atoms to form CeCa2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Ce(1)Ca2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Ca(1)Ce2Mg10 cuboctahedra; edges with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; edges with four equivalent Mg(7)CeMg11 cuboctahedra; edges with eight Mg(5,5,5,5)CaCeMg10 cuboctahedra; faces with two equivalent Ca(1)Ce2Mg10 cuboctahedra; faces with two equivalent Mg(7)CeMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(3,3,3)Ca2Ce2Mg8 cuboctahedra; faces with four Mg(5,5,5)CaCeMg10 cuboctahedra; and faces with six equivalent Mg(6)CaMg11 cuboctahedra.