Sr3Cu8Sn4 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3mc space group. Sr(1) is bonded in a 14-coordinate geometry to two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(1), two equivalent Sn(2), and four equivalent Sn(1) atoms. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 12-coordinate geometry to four equivalent Sr(1), one Cu(4), three equivalent Cu(2), one Sn(2), and three equivalent Sn(1) atoms. In the second Cu site, Cu(2) is bonded to two equivalent Sr(1), two equivalent Cu(2), two equivalent Cu(4), three equivalent Cu(1), and three equivalent Sn(1) atoms to form distorted CuSr2Cu7Sn3 cuboctahedra that share corners with four equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, corners with five equivalent Sn(1)Sr4Cu8 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with six equivalent Sn(1)Sr4Cu8 cuboctahedra. In the third Cu site, Cu(3) is bonded in a distorted q6 geometry to six equivalent Sr(1), one Sn(2), and three equivalent Sn(1) atoms. In the fourth Cu site, Cu(4) is bonded to three equivalent Cu(1), six equivalent Cu(2), and three equivalent Sn(1) atoms to form CuCu9Sn3 cuboctahedra that share corners with three equivalent Sn(1)Sr4Cu8 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with six equivalent Sn(1)Sr4Cu8 cuboctahedra. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to four equivalent Sr(1), one Cu(3), one Cu(4), three equivalent Cu(1), and three equivalent Cu(2) atoms to form distorted SnSr4Cu8 cuboctahedra that share  a cornercorner with one Cu(4)Cu9Sn3 cuboctahedra, corners with four equivalent Sn(1)Sr4Cu8 cuboctahedra, corners with five equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with eight equivalent Sn(1)Sr4Cu8 cuboctahedra. In the second Sn site, Sn(2) is bonded in a 10-coordinate geometry to six equivalent Sr(1), one Cu(3), and three equivalent Cu(1) atoms.
Sr3Cu8Sn4 is Hexagonal Laves-derived structured and crystallizes in the hexagonal P6_3mc space group. Sr(1) is bonded in a 14-coordinate geometry to two equivalent Cu(2), two equivalent Cu(3), four equivalent Cu(1), two equivalent Sn(2), and four equivalent Sn(1) atoms. Both Sr(1)-Cu(2) bond lengths are 3.34 Å. There is one shorter (3.39 Å) and one longer (3.53 Å) Sr(1)-Cu(3) bond length. There are two shorter (3.28 Å) and two longer (3.67 Å) Sr(1)-Cu(1) bond lengths. There is one shorter (3.42 Å) and one longer (3.45 Å) Sr(1)-Sn(2) bond length. There are two shorter (3.37 Å) and two longer (3.46 Å) Sr(1)-Sn(1) bond lengths. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 12-coordinate geometry to four equivalent Sr(1), one Cu(4), three equivalent Cu(2), one Sn(2), and three equivalent Sn(1) atoms. The Cu(1)-Cu(4) bond length is 2.65 Å. There is one shorter (2.65 Å) and two longer (2.75 Å) Cu(1)-Cu(2) bond lengths. The Cu(1)-Sn(2) bond length is 2.80 Å. There are two shorter (2.83 Å) and one longer (3.02 Å) Cu(1)-Sn(1) bond length. In the second Cu site, Cu(2) is bonded to two equivalent Sr(1), two equivalent Cu(2), two equivalent Cu(4), three equivalent Cu(1), and three equivalent Sn(1) atoms to form distorted CuSr2Cu7Sn3 cuboctahedra that share corners with four equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, corners with five equivalent Sn(1)Sr4Cu8 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with six equivalent Sn(1)Sr4Cu8 cuboctahedra. Both Cu(2)-Cu(2) bond lengths are 2.76 Å. There is one shorter (2.53 Å) and one longer (2.57 Å) Cu(2)-Cu(4) bond length. There is one shorter (2.74 Å) and two longer (2.77 Å) Cu(2)-Sn(1) bond lengths. In the third Cu site, Cu(3) is bonded in a distorted q6 geometry to six equivalent Sr(1), one Sn(2), and three equivalent Sn(1) atoms. The Cu(3)-Sn(2) bond length is 2.76 Å. All Cu(3)-Sn(1) bond lengths are 2.75 Å. In the fourth Cu site, Cu(4) is bonded to three equivalent Cu(1), six equivalent Cu(2), and three equivalent Sn(1) atoms to form CuCu9Sn3 cuboctahedra that share corners with three equivalent Sn(1)Sr4Cu8 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with six equivalent Sn(1)Sr4Cu8 cuboctahedra. All Cu(4)-Sn(1) bond lengths are 2.74 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to four equivalent Sr(1), one Cu(3), one Cu(4), three equivalent Cu(1), and three equivalent Cu(2) atoms to form distorted SnSr4Cu8 cuboctahedra that share  a cornercorner with one Cu(4)Cu9Sn3 cuboctahedra, corners with four equivalent Sn(1)Sr4Cu8 cuboctahedra, corners with five equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, faces with two equivalent Cu(4)Cu9Sn3 cuboctahedra, faces with six equivalent Cu(2)Sr2Cu7Sn3 cuboctahedra, and faces with eight equivalent Sn(1)Sr4Cu8 cuboctahedra. In the second Sn site, Sn(2) is bonded in a 10-coordinate geometry to six equivalent Sr(1), one Cu(3), and three equivalent Cu(1) atoms.