SrMg14Sn crystallizes in the orthorhombic Amm2 space group. Sr(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Sn(1) atoms to form SrMg10Sn2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Sr(1)Mg10Sn2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Sr(1)Mg10Sn2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(5)SrMg10Sn cuboctahedra, and faces with six equivalent Mg(7)SrMg11 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Sn(1)Sr2Mg10 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Sr(1), two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and two equivalent Sn(1) atoms to form distorted MgSr2Mg8Sn2 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)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(5)SrMg10Sn cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, and faces with eight equivalent Mg(5)SrMg10Sn 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 Sr(1)Mg10Sn2 cuboctahedra, corners with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, corners with four equivalent Sn(1)Sr2Mg10 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)SrMg10Sn cuboctahedra, edges with four equivalent Mg(7)SrMg11 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)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, and faces with eight equivalent Mg(5)SrMg10Sn cuboctahedra. In the fifth Mg site, Mg(5) is bonded to one Sr(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 Sn(1) atom to form distorted MgSrMg10Sn cuboctahedra that share corners with four equivalent Mg(7)SrMg11 cuboctahedra, corners with ten equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 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)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Mg(7)SrMg11 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra,  a faceface with one Sr(1)Mg10Sn2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one Sn(1)Sr2Mg10 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. In the sixth Mg site, Mg(6) is bonded in a distorted single-bond geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Sn(1) atom. In the seventh Mg site, Mg(7) is bonded to one Sr(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), and four equivalent Mg(5) atoms to form distorted MgSrMg11 cuboctahedra that share corners with six equivalent Mg(7)SrMg11 cuboctahedra, corners with eight equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with four equivalent Mg(5)SrMg10Sn cuboctahedra,  a faceface with one Sr(1)Mg10Sn2 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with three equivalent Mg(1)Mg12 cuboctahedra, faces with three equivalent Sn(1)Sr2Mg10 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. Sn(1) is bonded to two equivalent Sr(1), two equivalent Mg(6), four equivalent Mg(3), and four equivalent Mg(5) atoms to form SnSr2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Sn(1)Sr2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with four equivalent Mg(5)SrMg10Sn cuboctahedra, and faces with six equivalent Mg(7)SrMg11 cuboctahedra.
SrMg14Sn crystallizes in the orthorhombic Amm2 space group. Sr(1) is bonded to two equivalent Mg(7), four equivalent Mg(3), four equivalent Mg(5), and two equivalent Sn(1) atoms to form SrMg10Sn2 cuboctahedra that share corners with four equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Sr(1)Mg10Sn2 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. Both Sr(1)-Mg(7) bond lengths are 3.37 Å. There are two shorter (3.28 Å) and two longer (3.30 Å) Sr(1)-Mg(3) bond lengths. All Sr(1)-Mg(5) bond lengths are 3.36 Å. Both Sr(1)-Sn(1) bond lengths are 3.25 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), two equivalent Mg(6), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Sr(1)Mg10Sn2 cuboctahedra, corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Mg(2)Mg12 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(5)SrMg10Sn cuboctahedra, and faces with six equivalent Mg(7)SrMg11 cuboctahedra. Both Mg(1)-Mg(2) bond lengths are 3.24 Å. Both Mg(1)-Mg(6) bond lengths are 3.27 Å. There are two shorter (3.26 Å) and two longer (3.31 Å) Mg(1)-Mg(4) bond lengths. All Mg(1)-Mg(5) bond lengths are 3.15 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(7), four equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with four equivalent Sn(1)Sr2Mg10 cuboctahedra, corners with six equivalent Mg(2)Mg12 cuboctahedra, corners with eight equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. Both Mg(2)-Mg(7) bond lengths are 3.19 Å. All Mg(2)-Mg(4) bond lengths are 3.29 Å. All Mg(2)-Mg(5) bond lengths are 3.18 Å. In the third Mg site, Mg(3) is bonded to two equivalent Sr(1), two equivalent Mg(3), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), and two equivalent Sn(1) atoms to form distorted MgSr2Mg8Sn2 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)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra, edges with four equivalent Mg(5)SrMg10Sn cuboctahedra, edges with four equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with two equivalent Sn(1)Sr2Mg10 cuboctahedra, and faces with eight equivalent Mg(5)SrMg10Sn cuboctahedra. There is one shorter (3.18 Å) and one longer (3.31 Å) Mg(3)-Mg(3) bond length. Both Mg(3)-Mg(5) bond lengths are 3.33 Å. Both Mg(3)-Mg(6) bond lengths are 3.24 Å. Both Mg(3)-Mg(7) bond lengths are 3.32 Å. There is one shorter (3.20 Å) and one longer (3.38 Å) Mg(3)-Sn(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 Sr(1)Mg10Sn2 cuboctahedra, corners with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, corners with four equivalent Sn(1)Sr2Mg10 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)SrMg10Sn cuboctahedra, edges with four equivalent Mg(7)SrMg11 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)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, and faces with eight equivalent Mg(5)SrMg10Sn cuboctahedra. There is one shorter (3.22 Å) and one longer (3.27 Å) Mg(4)-Mg(4) bond length. Both Mg(4)-Mg(5) bond lengths are 3.16 Å. Both Mg(4)-Mg(6) bond lengths are 3.26 Å. Both Mg(4)-Mg(7) bond lengths are 3.14 Å. In the fifth Mg site, Mg(5) is bonded to one Sr(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 Sn(1) atom to form distorted MgSrMg10Sn cuboctahedra that share corners with four equivalent Mg(7)SrMg11 cuboctahedra, corners with ten equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 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)Sr2Mg8Sn2 cuboctahedra, edges with two equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Mg(7)SrMg11 cuboctahedra, edges with two equivalent Sn(1)Sr2Mg10 cuboctahedra,  a faceface with one Sr(1)Mg10Sn2 cuboctahedra,  a faceface with one Mg(1)Mg12 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra,  a faceface with one Sn(1)Sr2Mg10 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with four equivalent Mg(4)Mg12 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. There is one shorter (3.19 Å) and one longer (3.30 Å) Mg(5)-Mg(5) bond length. There is one shorter (3.28 Å) and one longer (3.30 Å) Mg(5)-Mg(6) bond length. There is one shorter (3.22 Å) and one longer (3.35 Å) Mg(5)-Mg(7) bond length. The Mg(5)-Sn(1) bond length is 3.31 Å. In the sixth Mg site, Mg(6) is bonded in a distorted single-bond geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(7), four equivalent Mg(5), and one Sn(1) atom. Both Mg(6)-Mg(7) bond lengths are 3.25 Å. The Mg(6)-Sn(1) bond length is 3.28 Å. In the seventh Mg site, Mg(7) is bonded to one Sr(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(6), and four equivalent Mg(5) atoms to form distorted MgSrMg11 cuboctahedra that share corners with six equivalent Mg(7)SrMg11 cuboctahedra, corners with eight equivalent Mg(5)SrMg10Sn cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with two equivalent Mg(2)Mg12 cuboctahedra, edges with four equivalent Mg(4)Mg12 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with four equivalent Mg(5)SrMg10Sn cuboctahedra,  a faceface with one Sr(1)Mg10Sn2 cuboctahedra,  a faceface with one Mg(2)Mg12 cuboctahedra, faces with two equivalent Mg(4)Mg12 cuboctahedra, faces with two equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with two equivalent Mg(7)SrMg11 cuboctahedra, faces with three equivalent Mg(1)Mg12 cuboctahedra, faces with three equivalent Sn(1)Sr2Mg10 cuboctahedra, and faces with four equivalent Mg(5)SrMg10Sn cuboctahedra. Sn(1) is bonded to two equivalent Sr(1), two equivalent Mg(6), four equivalent Mg(3), and four equivalent Mg(5) atoms to form SnSr2Mg10 cuboctahedra that share corners with four equivalent Mg(2)Mg12 cuboctahedra, corners with six equivalent Sn(1)Sr2Mg10 cuboctahedra, corners with eight equivalent Mg(4)Mg12 cuboctahedra, edges with two equivalent Sr(1)Mg10Sn2 cuboctahedra, edges with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, edges with eight equivalent Mg(5)SrMg10Sn cuboctahedra, faces with two equivalent Sr(1)Mg10Sn2 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(3)Sr2Mg8Sn2 cuboctahedra, faces with four equivalent Mg(5)SrMg10Sn cuboctahedra, and faces with six equivalent Mg(7)SrMg11 cuboctahedra.