Mg14CrSi crystallizes in the orthorhombic Amm2 space group. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Cr cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Mg10Cr2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Si cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Cr(1), and two equivalent Si(1) atoms to form distorted MgMg8Cr2Si2 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)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four Mg(5,5)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CrSi 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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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 Mg(5,5)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CrSi cuboctahedra. In the fifth 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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight Mg(5,5)Mg10CrSi cuboctahedra. In the sixth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cr(1), and one Si(1) atom to form distorted MgMg10CrSi cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with ten equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(6)Mg11Si 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 Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra. In the seventh Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four equivalent Mg(5); and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with six equivalent Mg(6)Mg11Si cuboctahedra; corners with eight Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four equivalent Mg(5)Mg10CrSi cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Cr(1)Mg10Si2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CrSi cuboctahedra. In the eighth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); four equivalent Mg(5); and one Cr(1) atom to form distorted MgMg11Cr cuboctahedra that share corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with six equivalent Mg(7)Mg11Cr cuboctahedra; corners with eight Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(6)Mg11Si cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(5)Mg10CrSi cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; faces with three equivalent Si(1)Mg10Cr2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CrSi cuboctahedra. In the ninth 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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight Mg(5,5)Mg10CrSi cuboctahedra. In the tenth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cr(1), and one Si(1) atom to form distorted MgMg10CrSi cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with ten Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(6)Mg11Si 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 Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra. Cr(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Si(1) atoms to form CrMg10Si2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Cr(1)Mg10Si2 cuboctahedra; corners with eight Mg(4,4,4)Mg12 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Si(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cr(1) atoms to form SiMg10Cr2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Si(1)Mg10Cr2 cuboctahedra; corners with eight Mg(4,4,4)Mg12 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with six equivalent Mg(7)Mg11Cr cuboctahedra.
Mg14CrSi crystallizes in the orthorhombic Amm2 space group. There are ten inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2); two equivalent Mg(6); four Mg(4,4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Cr cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.11 Å. Both Mg(1)-Mg(6) bond lengths are 3.15 Å. There are two shorter (3.12 Å) and two longer (3.13 Å) Mg(1)-Mg(4,4,4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.19 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1); two equivalent Mg(7); four Mg(4,4,4); and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Mg10Cr2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.14 Å. There are two shorter (3.11 Å) and two longer (3.14 Å) Mg(2)-Mg(4,4,4) bond lengths. All Mg(2)-Mg(5) bond lengths are 3.20 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Cr(1), and two equivalent Si(1) atoms to form distorted MgMg8Cr2Si2 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)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four Mg(5,5)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CrSi cuboctahedra. There is one shorter (3.10 Å) and one longer (3.13 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5) bond lengths are 3.07 Å. Both Mg(3)-Mg(6) bond lengths are 3.10 Å. Both Mg(3)-Mg(7) bond lengths are 3.11 Å. There is one shorter (3.10 Å) and one longer (3.15 Å) Mg(3)-Cr(1) bond length. There is one shorter (3.10 Å) and one longer (3.15 Å) Mg(3)-Si(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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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 Mg(5,5)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight equivalent Mg(5)Mg10CrSi cuboctahedra. There is one shorter (3.11 Å) and one longer (3.12 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.16 Å. Both Mg(4)-Mg(7) bond lengths are 3.15 Å. In the fifth 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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight Mg(5,5)Mg10CrSi cuboctahedra. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.16 Å. Both Mg(4)-Mg(7) bond lengths are 3.15 Å. In the sixth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cr(1), and one Si(1) atom to form distorted MgMg10CrSi cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with ten equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(6)Mg11Si 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 Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra. There is one shorter (3.10 Å) and one longer (3.12 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.08 Å) and one longer (3.16 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.09 Å) and one longer (3.16 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Cr(1) bond length is 3.04 Å. The Mg(5)-Si(1) bond length is 3.04 Å. In the seventh Mg site, Mg(6) is bonded to one Mg(1); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(7); four equivalent Mg(5); and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with six equivalent Mg(6)Mg11Si cuboctahedra; corners with eight Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four equivalent Mg(5)Mg10CrSi cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Cr(1)Mg10Si2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CrSi cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.11 Å. The Mg(6)-Si(1) bond length is 3.07 Å. In the eighth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two Mg(4,4); two equivalent Mg(6); four equivalent Mg(5); and one Cr(1) atom to form distorted MgMg11Cr cuboctahedra that share corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with six equivalent Mg(7)Mg11Cr cuboctahedra; corners with eight Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(6)Mg11Si cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(5)Mg10CrSi cuboctahedra; edges with four Mg(4,4,4)Mg12 cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two Mg(4,4)Mg12 cuboctahedra; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; faces with three equivalent Si(1)Mg10Cr2 cuboctahedra; and faces with four equivalent Mg(5)Mg10CrSi cuboctahedra. The Mg(7)-Cr(1) bond length is 3.09 Å. In the ninth 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 Mg(3)Mg8Cr2Si2 cuboctahedra; corners with four equivalent Cr(1)Mg10Si2 cuboctahedra; corners with four equivalent Si(1)Mg10Cr2 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)Mg10CrSi cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si 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; faces with two equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with eight Mg(5,5)Mg10CrSi cuboctahedra. There is one shorter (3.11 Å) and one longer (3.12 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.16 Å. Both Mg(4)-Mg(7) bond lengths are 3.15 Å. In the tenth Mg site, Mg(5) is bonded to one Mg(1), one Mg(2), one Mg(3), one Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), one Cr(1), and one Si(1) atom to form distorted MgMg10CrSi cuboctahedra that share corners with four equivalent Mg(7)Mg11Cr cuboctahedra; corners with four equivalent Mg(6)Mg11Si cuboctahedra; corners with ten Mg(5,5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(5)Mg10CrSi cuboctahedra; edges with two equivalent Mg(7)Mg11Cr cuboctahedra; edges with two equivalent Mg(6)Mg11Si 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 Mg(3)Mg8Cr2Si2 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Cr(1)Mg10Si2 cuboctahedra;  a faceface with one Si(1)Mg10Cr2 cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four Mg(4,4,4)Mg12 cuboctahedra; and faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra. The Mg(5)-Mg(1) bond length is 3.19 Å. The Mg(5)-Mg(2) bond length is 3.20 Å. The Mg(5)-Mg(3) bond length is 3.07 Å. The Mg(5)-Mg(4) bond length is 3.22 Å. There is one shorter (3.10 Å) and one longer (3.12 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.08 Å) and one longer (3.16 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.09 Å) and one longer (3.16 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Cr(1) bond length is 3.04 Å. The Mg(5)-Si(1) bond length is 3.04 Å. Cr(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Si(1) atoms to form CrMg10Si2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Cr(1)Mg10Si2 cuboctahedra; corners with eight Mg(4,4,4)Mg12 cuboctahedra; edges with two equivalent Si(1)Mg10Cr2 cuboctahedra; edges with four equivalent Mg(7)Mg11Cr cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(7)Mg11Cr cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with two equivalent Si(1)Mg10Cr2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with six equivalent Mg(6)Mg11Si cuboctahedra. Both Cr(1)-Si(1) bond lengths are 3.11 Å. Si(1) is bonded to two equivalent Mg(6), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Cr(1) atoms to form SiMg10Cr2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Si(1)Mg10Cr2 cuboctahedra; corners with eight Mg(4,4,4)Mg12 cuboctahedra; edges with two equivalent Cr(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(6)Mg11Si cuboctahedra; edges with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; edges with eight Mg(5,5)Mg10CrSi cuboctahedra; faces with two equivalent Mg(6)Mg11Si cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Cr(1)Mg10Si2 cuboctahedra; faces with four equivalent Mg(5)Mg10CrSi cuboctahedra; faces with four equivalent Mg(3)Mg8Cr2Si2 cuboctahedra; and faces with six equivalent Mg(7)Mg11Cr cuboctahedra.