LiMg14Si crystallizes in the orthorhombic Amm2 space group. Li(1) is bonded to two equivalent Mg(6); four equivalent Mg(3); four Mg(5,5); and two equivalent Si(1) atoms to form LiMg10Si2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Li(1)Mg10Si2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with six equivalent Mg(7)Mg11Si cuboctahedra. There are nine 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) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Li2Mg10 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Si 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) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Li(1)Mg10Si2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)LiMg11 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Li(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Si(1) atoms to form distorted MgLi2Mg8Si2 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)Li2Mg8Si2 cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(5)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; and faces with eight Mg(5,5)LiMg10Si 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 Li(1)Mg10Si2 cuboctahedra; corners with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; corners with four equivalent Si(1)Li2Mg10 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(5)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)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; and faces with eight Mg(5,5)LiMg10Si 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 Li(1)Mg10Si2 cuboctahedra; corners with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; corners with four equivalent Si(1)Li2Mg10 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)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)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; and faces with eight Mg(5,5)LiMg10Si cuboctahedra. In the sixth Mg site, Mg(5) is bonded to one Li(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 Si(1) atom to form distorted MgLiMg10Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with ten Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(7)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 Si(1)Li2Mg10 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four equivalent Mg(5)LiMg10Si cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the seventh Mg site, Mg(5) is bonded to one Li(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 Si(1) atom to form distorted MgLiMg10Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with ten equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(7)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 Si(1)Li2Mg10 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. In the eighth Mg site, Mg(6) is bonded to one Li(1); one Mg(1); two equivalent Mg(3); two equivalent Mg(4); two equivalent Mg(7); and four Mg(5,5) atoms to form distorted MgLiMg11 cuboctahedra that share corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with six equivalent Mg(6)LiMg11 cuboctahedra; corners with eight Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(7)Mg11Si cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four Mg(5,5)LiMg10Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Si(1)Li2Mg10 cuboctahedra; and faces with four Mg(5,5)LiMg10Si cuboctahedra. In the ninth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two equivalent Mg(4); two equivalent Mg(6); four Mg(5,5); and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with six equivalent Mg(7)Mg11Si cuboctahedra; corners with eight Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four Mg(5,5)LiMg10Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Li(1)Mg10Si2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with four Mg(5,5)LiMg10Si cuboctahedra. Si(1) is bonded to two equivalent Li(1); two equivalent Mg(7); four equivalent Mg(3); and four Mg(5,5) atoms to form SiLi2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Si(1)Li2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with six equivalent Mg(6)LiMg11 cuboctahedra.
LiMg14Si crystallizes in the orthorhombic Amm2 space group. Li(1) is bonded to two equivalent Mg(6); four equivalent Mg(3); four Mg(5,5); and two equivalent Si(1) atoms to form LiMg10Si2 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra; corners with six equivalent Li(1)Mg10Si2 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with six equivalent Mg(7)Mg11Si cuboctahedra. Both Li(1)-Mg(6) bond lengths are 3.15 Å. There are two shorter (3.09 Å) and two longer (3.15 Å) Li(1)-Mg(3) bond lengths. All Li(1)-Mg(5,5) bond lengths are 3.08 Å. Both Li(1)-Si(1) bond lengths are 3.14 Å. There are nine 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) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Si(1)Li2Mg10 cuboctahedra; corners with six equivalent Mg(1)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(7)Mg11Si cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.14 Å. Both Mg(1)-Mg(6) bond lengths are 3.13 Å. There are two shorter (3.10 Å) and two longer (3.14 Å) Mg(1)-Mg(4,4) bond lengths. All Mg(1)-Mg(5,5) bond lengths are 3.21 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) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Li(1)Mg10Si2 cuboctahedra; corners with six equivalent Mg(2)Mg12 cuboctahedra; corners with eight equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(1)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; faces with four Mg(4,4)Mg12 cuboctahedra; and faces with six equivalent Mg(6)LiMg11 cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.18 Å. All Mg(2)-Mg(4,4) bond lengths are 3.12 Å. All Mg(2)-Mg(5,5) bond lengths are 3.20 Å. In the third Mg site, Mg(3) is bonded to two equivalent Li(1); two equivalent Mg(3); two Mg(5,5); two equivalent Mg(6); two equivalent Mg(7); and two equivalent Si(1) atoms to form distorted MgLi2Mg8Si2 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)Li2Mg8Si2 cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(5)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with two equivalent Si(1)Li2Mg10 cuboctahedra; and faces with eight Mg(5,5)LiMg10Si cuboctahedra. There is one shorter (3.11 Å) and one longer (3.17 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5,5) bond lengths are 3.10 Å. Both Mg(3)-Mg(6) bond lengths are 3.15 Å. Both Mg(3)-Mg(7) bond lengths are 3.10 Å. There is one shorter (3.11 Å) and one longer (3.12 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 Mg(5,5); two equivalent Mg(6); and two equivalent Mg(7) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Li(1)Mg10Si2 cuboctahedra; corners with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; corners with four equivalent Si(1)Li2Mg10 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(5)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)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; and faces with eight Mg(5,5)LiMg10Si cuboctahedra. There is one shorter (3.12 Å) and one longer (3.16 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5,5) bond lengths are 3.22 Å. Both Mg(4)-Mg(6) bond lengths are 3.14 Å. Both Mg(4)-Mg(7) bond lengths are 3.20 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 Li(1)Mg10Si2 cuboctahedra; corners with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; corners with four equivalent Si(1)Li2Mg10 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)LiMg10Si cuboctahedra; edges with four equivalent Mg(6)LiMg11 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)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; and faces with eight Mg(5,5)LiMg10Si cuboctahedra. There is one shorter (3.12 Å) and one longer (3.16 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 3.14 Å. Both Mg(4)-Mg(7) bond lengths are 3.20 Å. In the sixth Mg site, Mg(5) is bonded to one Li(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 Si(1) atom to form distorted MgLiMg10Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with ten Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(7)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 Si(1)Li2Mg10 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four equivalent Mg(5)LiMg10Si cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. There is one shorter (3.11 Å) and one longer (3.17 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.10 Å) and one longer (3.14 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.07 Å) and one longer (3.17 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Si(1) bond length is 3.06 Å. In the seventh Mg site, Mg(5) is bonded to one Li(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 Si(1) atom to form distorted MgLiMg10Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with ten equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with two equivalent Mg(5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(7)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 Si(1)Li2Mg10 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with four Mg(4,4)Mg12 cuboctahedra. There is one shorter (3.11 Å) and one longer (3.17 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.10 Å) and one longer (3.14 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.07 Å) and one longer (3.17 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Si(1) bond length is 3.06 Å. In the eighth Mg site, Mg(6) is bonded to one Li(1); one Mg(1); two equivalent Mg(3); two equivalent Mg(4); two equivalent Mg(7); and four Mg(5,5) atoms to form distorted MgLiMg11 cuboctahedra that share corners with four equivalent Mg(7)Mg11Si cuboctahedra; corners with six equivalent Mg(6)LiMg11 cuboctahedra; corners with eight Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with two equivalent Mg(7)Mg11Si cuboctahedra; edges with two equivalent Mg(1)Mg12 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four Mg(5,5)LiMg10Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Li(1)Mg10Si2 cuboctahedra;  a faceface with one Mg(1)Mg12 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Mg(2)Mg12 cuboctahedra; faces with three equivalent Si(1)Li2Mg10 cuboctahedra; and faces with four Mg(5,5)LiMg10Si cuboctahedra. Both Mg(6)-Mg(7) bond lengths are 3.14 Å. In the ninth Mg site, Mg(7) is bonded to one Mg(2); two equivalent Mg(3); two equivalent Mg(4); two equivalent Mg(6); four Mg(5,5); and one Si(1) atom to form distorted MgMg11Si cuboctahedra that share corners with four equivalent Mg(6)LiMg11 cuboctahedra; corners with six equivalent Mg(7)Mg11Si cuboctahedra; corners with eight Mg(5,5)LiMg10Si cuboctahedra; edges with two equivalent Mg(6)LiMg11 cuboctahedra; edges with two equivalent Mg(2)Mg12 cuboctahedra; edges with two equivalent Si(1)Li2Mg10 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four Mg(5,5)LiMg10Si cuboctahedra; edges with four Mg(4,4)Mg12 cuboctahedra;  a faceface with one Mg(2)Mg12 cuboctahedra;  a faceface with one Si(1)Li2Mg10 cuboctahedra; faces with two equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with two equivalent Mg(6)LiMg11 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(4)Mg12 cuboctahedra; faces with three equivalent Li(1)Mg10Si2 cuboctahedra; faces with three equivalent Mg(1)Mg12 cuboctahedra; and faces with four Mg(5,5)LiMg10Si cuboctahedra. The Mg(7)-Si(1) bond length is 3.08 Å. Si(1) is bonded to two equivalent Li(1); two equivalent Mg(7); four equivalent Mg(3); and four Mg(5,5) atoms to form SiLi2Mg10 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra; corners with six equivalent Si(1)Li2Mg10 cuboctahedra; corners with eight Mg(4,4)Mg12 cuboctahedra; edges with two equivalent Li(1)Mg10Si2 cuboctahedra; edges with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; edges with four equivalent Mg(7)Mg11Si cuboctahedra; edges with eight Mg(5,5)LiMg10Si cuboctahedra; faces with two equivalent Li(1)Mg10Si2 cuboctahedra; faces with two equivalent Mg(7)Mg11Si cuboctahedra; faces with two equivalent Mg(2)Mg12 cuboctahedra; faces with four equivalent Mg(3)Li2Mg8Si2 cuboctahedra; faces with four Mg(5,5)LiMg10Si cuboctahedra; and faces with six equivalent Mg(6)LiMg11 cuboctahedra.