Sr4Au7Sn9 crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 16-coordinate geometry to two equivalent Au(4), four equivalent Au(1), two equivalent Sn(3), two equivalent Sn(4), two equivalent Sn(5), and four equivalent Sn(1) atoms. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to two equivalent Au(3), two equivalent Au(5), four equivalent Au(2), two equivalent Sn(3), two equivalent Sn(4), and four equivalent Sn(2) atoms. There are seven inequivalent Au sites. In the first Au site, Au(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Sn(1), two equivalent Sn(3), and two equivalent Sn(4) atoms. In the second Au site, Au(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), one Sn(2), two equivalent Sn(3), and two equivalent Sn(4) atoms. In the third Au site, Au(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Sn(1), two equivalent Sn(3), and two equivalent Sn(4) atoms. In the fourth Au site, Au(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), one Sn(2), two equivalent Sn(3), and two equivalent Sn(4) atoms. In the fifth Au site, Au(3) is bonded in a 8-coordinate geometry to four equivalent Sr(2) and four equivalent Sn(2) atoms. In the sixth Au site, Au(4) is bonded to four equivalent Sr(1), four equivalent Sn(1), and four equivalent Sn(5) atoms to form distorted AuSr4Sn8 tetrahedra that share corners with four equivalent Au(4)Sr4Sn8 tetrahedra, corners with four equivalent Sn(4)Sr4Au4 tetrahedra, corners with eight equivalent Sn(3)Sr4Au4 tetrahedra, edges with two equivalent Sn(4)Sr4Au4 tetrahedra, faces with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, and faces with four equivalent Au(4)Sr4Sn8 tetrahedra. In the seventh Au site, Au(5) is bonded in a 8-coordinate geometry to four equivalent Sr(2) and four equivalent Sn(2) atoms. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Au(1), two equivalent Au(4), and two equivalent Sn(5) atoms. In the second Sn site, Sn(2) is bonded in a 5-coordinate geometry to four equivalent Sr(2), one Au(2), two equivalent Au(3), and two equivalent Au(5) atoms. In the third Sn site, Sn(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Au(1), and two equivalent Au(2) atoms to form distorted SnSr4Au4 tetrahedra that share corners with two equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with four equivalent Au(4)Sr4Sn8 tetrahedra,  an edgeedge with one Sn(5)Sr4Sn4Au4 cuboctahedra, edges with four equivalent Sn(3)Sr4Au4 tetrahedra, and faces with four equivalent Sn(4)Sr4Au4 tetrahedra. In the fourth Sn site, Sn(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Au(1), and two equivalent Au(2) atoms to form distorted SnSr4Au4 tetrahedra that share corners with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with two equivalent Au(4)Sr4Sn8 tetrahedra,  an edgeedge with one Au(4)Sr4Sn8 tetrahedra, edges with four equivalent Sn(4)Sr4Au4 tetrahedra, and faces with four equivalent Sn(3)Sr4Au4 tetrahedra. In the fifth Sn site, Sn(5) is bonded to four equivalent Sr(1), four equivalent Au(4), and four equivalent Sn(1) atoms to form SnSr4Sn4Au4 cuboctahedra that share corners with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with four equivalent Sn(3)Sr4Au4 tetrahedra, corners with eight equivalent Sn(4)Sr4Au4 tetrahedra, edges with two equivalent Sn(3)Sr4Au4 tetrahedra, faces with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, and faces with four equivalent Au(4)Sr4Sn8 tetrahedra.
Sr4Au7Sn9 crystallizes in the tetragonal P-4m2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 16-coordinate geometry to two equivalent Au(4), four equivalent Au(1), two equivalent Sn(3), two equivalent Sn(4), two equivalent Sn(5), and four equivalent Sn(1) atoms. Both Sr(1)-Au(4) bond lengths are 3.83 Å. All Sr(1)-Au(1) bond lengths are 3.66 Å. Both Sr(1)-Sn(3) bond lengths are 3.74 Å. Both Sr(1)-Sn(4) bond lengths are 3.75 Å. Both Sr(1)-Sn(5) bond lengths are 3.83 Å. All Sr(1)-Sn(1) bond lengths are 3.66 Å. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to two equivalent Au(3), two equivalent Au(5), four equivalent Au(2), two equivalent Sn(3), two equivalent Sn(4), and four equivalent Sn(2) atoms. Both Sr(2)-Au(3) bond lengths are 3.61 Å. Both Sr(2)-Au(5) bond lengths are 3.61 Å. All Sr(2)-Au(2) bond lengths are 3.71 Å. Both Sr(2)-Sn(3) bond lengths are 3.81 Å. Both Sr(2)-Sn(4) bond lengths are 3.80 Å. All Sr(2)-Sn(2) bond lengths are 3.63 Å. There are seven inequivalent Au sites. In the first Au site, Au(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Sn(1), two equivalent Sn(3), and two equivalent Sn(4) atoms. All Au(1)-Sr(1) bond lengths are 3.66 Å. The Au(1)-Sn(1) bond length is 2.68 Å. Both Au(1)-Sn(3) bond lengths are 2.85 Å. Both Au(1)-Sn(4) bond lengths are 2.85 Å. In the second Au site, Au(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), one Sn(2), two equivalent Sn(3), and two equivalent Sn(4) atoms. All Au(2)-Sr(2) bond lengths are 3.71 Å. The Au(2)-Sn(2) bond length is 2.71 Å. Both Au(2)-Sn(3) bond lengths are 2.83 Å. Both Au(2)-Sn(4) bond lengths are 2.83 Å. In the third Au site, Au(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Sn(1), two equivalent Sn(3), and two equivalent Sn(4) atoms. The Au(1)-Sn(1) bond length is 2.68 Å. Both Au(1)-Sn(3) bond lengths are 2.85 Å. Both Au(1)-Sn(4) bond lengths are 2.85 Å. In the fourth Au site, Au(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), one Sn(2), two equivalent Sn(3), and two equivalent Sn(4) atoms. The Au(2)-Sn(2) bond length is 2.71 Å. Both Au(2)-Sn(3) bond lengths are 2.83 Å. Both Au(2)-Sn(4) bond lengths are 2.83 Å. In the fifth Au site, Au(3) is bonded in a 8-coordinate geometry to four equivalent Sr(2) and four equivalent Sn(2) atoms. All Au(3)-Sn(2) bond lengths are 2.81 Å. In the sixth Au site, Au(4) is bonded to four equivalent Sr(1), four equivalent Sn(1), and four equivalent Sn(5) atoms to form distorted AuSr4Sn8 tetrahedra that share corners with four equivalent Au(4)Sr4Sn8 tetrahedra, corners with four equivalent Sn(4)Sr4Au4 tetrahedra, corners with eight equivalent Sn(3)Sr4Au4 tetrahedra, edges with two equivalent Sn(4)Sr4Au4 tetrahedra, faces with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, and faces with four equivalent Au(4)Sr4Sn8 tetrahedra. All Au(4)-Sn(1) bond lengths are 2.91 Å. All Au(4)-Sn(5) bond lengths are 3.41 Å. In the seventh Au site, Au(5) is bonded in a 8-coordinate geometry to four equivalent Sr(2) and four equivalent Sn(2) atoms. All Au(5)-Sn(2) bond lengths are 2.81 Å. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Au(1), two equivalent Au(4), and two equivalent Sn(5) atoms. Both Sn(1)-Sn(5) bond lengths are 2.91 Å. In the second Sn site, Sn(2) is bonded in a 5-coordinate geometry to four equivalent Sr(2), one Au(2), two equivalent Au(3), and two equivalent Au(5) atoms. In the third Sn site, Sn(3) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Au(1), and two equivalent Au(2) atoms to form distorted SnSr4Au4 tetrahedra that share corners with two equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with four equivalent Au(4)Sr4Sn8 tetrahedra,  an edgeedge with one Sn(5)Sr4Sn4Au4 cuboctahedra, edges with four equivalent Sn(3)Sr4Au4 tetrahedra, and faces with four equivalent Sn(4)Sr4Au4 tetrahedra. In the fourth Sn site, Sn(4) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Au(1), and two equivalent Au(2) atoms to form distorted SnSr4Au4 tetrahedra that share corners with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with two equivalent Au(4)Sr4Sn8 tetrahedra,  an edgeedge with one Au(4)Sr4Sn8 tetrahedra, edges with four equivalent Sn(4)Sr4Au4 tetrahedra, and faces with four equivalent Sn(3)Sr4Au4 tetrahedra. In the fifth Sn site, Sn(5) is bonded to four equivalent Sr(1), four equivalent Au(4), and four equivalent Sn(1) atoms to form SnSr4Sn4Au4 cuboctahedra that share corners with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, corners with four equivalent Sn(3)Sr4Au4 tetrahedra, corners with eight equivalent Sn(4)Sr4Au4 tetrahedra, edges with two equivalent Sn(3)Sr4Au4 tetrahedra, faces with four equivalent Sn(5)Sr4Sn4Au4 cuboctahedra, and faces with four equivalent Au(4)Sr4Sn8 tetrahedra.