FeCu10Zn4(SnSe4)5 is Clathrate-derived structured and crystallizes in the monoclinic C2 space group. Fe(1) is bonded to two equivalent Se(10) and two equivalent Se(3) atoms to form FeSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with four equivalent Cu(5)Se4 tetrahedra, and corners with four equivalent Sn(3)Se4 tetrahedra. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(10), one Se(7), and two equivalent Se(5) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Fe(1)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with three equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(2), one Se(3), one Se(8), and one Se(9) atom to form CuSe4 tetrahedra that share  a cornercorner with one Fe(1)Se4 tetrahedra,  a cornercorner with one Zn(2)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, and corners with two equivalent Sn(3)Se4 tetrahedra. In the third Cu site, Cu(3) is bonded to one Se(1), one Se(4), and two equivalent Se(6) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Zn(2)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with three equivalent Zn(1)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one Se(1), one Se(4), one Se(8), and one Se(9) atom to form CuSe4 tetrahedra that share  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with two equivalent Sn(2)Se4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one Se(10), one Se(2), one Se(3), and one Se(7) atom to form CuSe4 tetrahedra that share  a cornercorner with one Zn(1)Se4 tetrahedra,  a cornercorner with one Zn(2)Se4 tetrahedra, corners with two equivalent Fe(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, and corners with two equivalent Sn(3)Se4 tetrahedra. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one Se(2), one Se(4), one Se(6), and one Se(9) atom to form ZnSe4 tetrahedra that share  a cornercorner with one Cu(5)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with two equivalent Sn(2)Se4 tetrahedra, and corners with three equivalent Cu(3)Se4 tetrahedra. In the second Zn site, Zn(2) is bonded to one Se(1), one Se(5), one Se(7), and one Se(8) atom to form ZnSe4 tetrahedra that share  a cornercorner with one Cu(2)Se4 tetrahedra,  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one Cu(5)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with two equivalent Sn(3)Se4 tetrahedra, and corners with three equivalent Cu(1)Se4 tetrahedra. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Se(1), one Se(2), one Se(6), and one Se(7) atom to form SnSe4 tetrahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra,  a cornercorner with one Cu(2)Se4 tetrahedra,  a cornercorner with one Cu(4)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Cu(3)Se4 tetrahedra. In the second Sn site, Sn(2) is bonded to two equivalent Se(4) and two equivalent Se(9) atoms to form SnSe4 tetrahedra that share corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with four equivalent Cu(4)Se4 tetrahedra, and corners with four equivalent Zn(1)Se4 tetrahedra. In the third Sn site, Sn(3) is bonded to one Se(10), one Se(3), one Se(5), and one Se(8) atom to form SnSe4 tetrahedra that share  a cornercorner with one Cu(4)Se4 tetrahedra, corners with two equivalent Fe(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Cu(1)Se4 tetrahedra. There are ten inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(3), one Cu(4), one Zn(2), and one Sn(1) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the second Se site, Se(2) is bonded to one Cu(2), one Cu(5), one Zn(1), and one Sn(1) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra,  a cornercorner with one Se(4)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(3)FeCu2Sn tetrahedra, corners with two equivalent Se(6)ZnCu2Sn tetrahedra, corners with two equivalent Se(7)ZnCu2Sn tetrahedra, and corners with two equivalent Se(9)ZnCu2Sn tetrahedra. In the third Se site, Se(3) is bonded to one Fe(1), one Cu(2), one Cu(5), and one Sn(3) atom to form SeFeCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(5)ZnCu2Sn tetrahedra,  a cornercorner with one Se(7)ZnCu2Sn tetrahedra,  a cornercorner with one Se(9)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, and corners with four equivalent Se(10)FeCu2Sn tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(3), one Cu(4), one Zn(1), and one Sn(2) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the fifth Se site, Se(5) is bonded to two equivalent Cu(1), one Zn(2), and one Sn(3) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(5)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, corners with three equivalent Se(10)FeCu2Sn tetrahedra, and corners with three equivalent Se(7)ZnCu2Sn tetrahedra. In the sixth Se site, Se(6) is bonded to two equivalent Cu(3), one Zn(1), and one Sn(1) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the seventh Se site, Se(7) is bonded to one Cu(1), one Cu(5), one Zn(2), and one Sn(1) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(6)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(10)FeCu2Sn tetrahedra, corners with two equivalent Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, and corners with three equivalent Se(5)ZnCu2Sn tetrahedra. In the eighth Se site, Se(8) is bonded to one Cu(2), one Cu(4), one Zn(2), and one Sn(3) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(2)ZnCu2Sn tetrahedra,  a cornercorner with one Se(4)ZnCu2Sn tetrahedra,  a cornercorner with one Se(7)ZnCu2Sn tetrahedra, corners with two equivalent Se(3)FeCu2Sn tetrahedra, corners with two equivalent Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(5)ZnCu2Sn tetrahedra, and corners with two equivalent Se(9)ZnCu2Sn tetrahedra. In the ninth Se site, Se(9) is bonded to one Cu(2), one Cu(4), one Zn(1), and one Sn(2) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra,  a cornercorner with one Se(6)ZnCu2Sn tetrahedra,  a cornercorner with one Se(9)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, and corners with four equivalent Se(4)ZnCu2Sn tetrahedra. In the tenth Se site, Se(10) is bonded to one Fe(1), one Cu(1), one Cu(5), and one Sn(3) atom to form SeFeCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(2)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(7)ZnCu2Sn tetrahedra, corners with three equivalent Se(5)ZnCu2Sn tetrahedra, and corners with four equivalent Se(3)FeCu2Sn tetrahedra.
FeCu10Zn4(SnSe4)5 is Clathrate-derived structured and crystallizes in the monoclinic C2 space group. Fe(1) is bonded to two equivalent Se(10) and two equivalent Se(3) atoms to form FeSe4 tetrahedra that share corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with four equivalent Cu(5)Se4 tetrahedra, and corners with four equivalent Sn(3)Se4 tetrahedra. Both Fe(1)-Se(10) bond lengths are 2.44 Å. Both Fe(1)-Se(3) bond lengths are 2.45 Å. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(10), one Se(7), and two equivalent Se(5) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Fe(1)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with three equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Sn(3)Se4 tetrahedra. The Cu(1)-Se(10) bond length is 2.45 Å. The Cu(1)-Se(7) bond length is 2.44 Å. There is one shorter (2.43 Å) and one longer (2.44 Å) Cu(1)-Se(5) bond length. In the second Cu site, Cu(2) is bonded to one Se(2), one Se(3), one Se(8), and one Se(9) atom to form CuSe4 tetrahedra that share  a cornercorner with one Fe(1)Se4 tetrahedra,  a cornercorner with one Zn(2)Se4 tetrahedra,  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, and corners with two equivalent Sn(3)Se4 tetrahedra. The Cu(2)-Se(2) bond length is 2.43 Å. The Cu(2)-Se(3) bond length is 2.45 Å. The Cu(2)-Se(8) bond length is 2.43 Å. The Cu(2)-Se(9) bond length is 2.44 Å. In the third Cu site, Cu(3) is bonded to one Se(1), one Se(4), and two equivalent Se(6) atoms to form CuSe4 tetrahedra that share  a cornercorner with one Zn(2)Se4 tetrahedra,  a cornercorner with one Sn(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with three equivalent Zn(1)Se4 tetrahedra, and corners with three equivalent Sn(1)Se4 tetrahedra. The Cu(3)-Se(1) bond length is 2.44 Å. The Cu(3)-Se(4) bond length is 2.43 Å. There is one shorter (2.43 Å) and one longer (2.44 Å) Cu(3)-Se(6) bond length. In the fourth Cu site, Cu(4) is bonded to one Se(1), one Se(4), one Se(8), and one Se(9) atom to form CuSe4 tetrahedra that share  a cornercorner with one Sn(1)Se4 tetrahedra,  a cornercorner with one Sn(3)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with two equivalent Sn(2)Se4 tetrahedra. The Cu(4)-Se(1) bond length is 2.43 Å. The Cu(4)-Se(4) bond length is 2.44 Å. The Cu(4)-Se(8) bond length is 2.44 Å. The Cu(4)-Se(9) bond length is 2.43 Å. In the fifth Cu site, Cu(5) is bonded to one Se(10), one Se(2), one Se(3), and one Se(7) atom to form CuSe4 tetrahedra that share  a cornercorner with one Zn(1)Se4 tetrahedra,  a cornercorner with one Zn(2)Se4 tetrahedra, corners with two equivalent Fe(1)Se4 tetrahedra, corners with two equivalent Cu(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, and corners with two equivalent Sn(3)Se4 tetrahedra. The Cu(5)-Se(10) bond length is 2.46 Å. The Cu(5)-Se(2) bond length is 2.44 Å. The Cu(5)-Se(3) bond length is 2.45 Å. The Cu(5)-Se(7) bond length is 2.43 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one Se(2), one Se(4), one Se(6), and one Se(9) atom to form ZnSe4 tetrahedra that share  a cornercorner with one Cu(5)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with two equivalent Sn(2)Se4 tetrahedra, and corners with three equivalent Cu(3)Se4 tetrahedra. The Zn(1)-Se(2) bond length is 2.51 Å. The Zn(1)-Se(4) bond length is 2.50 Å. The Zn(1)-Se(6) bond length is 2.50 Å. The Zn(1)-Se(9) bond length is 2.50 Å. In the second Zn site, Zn(2) is bonded to one Se(1), one Se(5), one Se(7), and one Se(8) atom to form ZnSe4 tetrahedra that share  a cornercorner with one Cu(2)Se4 tetrahedra,  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one Cu(5)Se4 tetrahedra, corners with two equivalent Cu(4)Se4 tetrahedra, corners with two equivalent Sn(1)Se4 tetrahedra, corners with two equivalent Sn(3)Se4 tetrahedra, and corners with three equivalent Cu(1)Se4 tetrahedra. The Zn(2)-Se(1) bond length is 2.50 Å. The Zn(2)-Se(5) bond length is 2.50 Å. The Zn(2)-Se(7) bond length is 2.50 Å. The Zn(2)-Se(8) bond length is 2.50 Å. There are three inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one Se(1), one Se(2), one Se(6), and one Se(7) atom to form SnSe4 tetrahedra that share  a cornercorner with one Cu(1)Se4 tetrahedra,  a cornercorner with one Cu(2)Se4 tetrahedra,  a cornercorner with one Cu(4)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(1)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Cu(3)Se4 tetrahedra. The Sn(1)-Se(1) bond length is 2.62 Å. The Sn(1)-Se(2) bond length is 2.62 Å. The Sn(1)-Se(6) bond length is 2.62 Å. The Sn(1)-Se(7) bond length is 2.63 Å. In the second Sn site, Sn(2) is bonded to two equivalent Se(4) and two equivalent Se(9) atoms to form SnSe4 tetrahedra that share corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(3)Se4 tetrahedra, corners with four equivalent Cu(4)Se4 tetrahedra, and corners with four equivalent Zn(1)Se4 tetrahedra. Both Sn(2)-Se(4) bond lengths are 2.62 Å. Both Sn(2)-Se(9) bond lengths are 2.63 Å. In the third Sn site, Sn(3) is bonded to one Se(10), one Se(3), one Se(5), and one Se(8) atom to form SnSe4 tetrahedra that share  a cornercorner with one Cu(4)Se4 tetrahedra, corners with two equivalent Fe(1)Se4 tetrahedra, corners with two equivalent Cu(2)Se4 tetrahedra, corners with two equivalent Cu(5)Se4 tetrahedra, corners with two equivalent Zn(2)Se4 tetrahedra, and corners with three equivalent Cu(1)Se4 tetrahedra. The Sn(3)-Se(10) bond length is 2.65 Å. The Sn(3)-Se(3) bond length is 2.64 Å. The Sn(3)-Se(5) bond length is 2.63 Å. The Sn(3)-Se(8) bond length is 2.63 Å. There are ten inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(3), one Cu(4), one Zn(2), and one Sn(1) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the second Se site, Se(2) is bonded to one Cu(2), one Cu(5), one Zn(1), and one Sn(1) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra,  a cornercorner with one Se(4)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(3)FeCu2Sn tetrahedra, corners with two equivalent Se(6)ZnCu2Sn tetrahedra, corners with two equivalent Se(7)ZnCu2Sn tetrahedra, and corners with two equivalent Se(9)ZnCu2Sn tetrahedra. In the third Se site, Se(3) is bonded to one Fe(1), one Cu(2), one Cu(5), and one Sn(3) atom to form SeFeCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(5)ZnCu2Sn tetrahedra,  a cornercorner with one Se(7)ZnCu2Sn tetrahedra,  a cornercorner with one Se(9)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, and corners with four equivalent Se(10)FeCu2Sn tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(3), one Cu(4), one Zn(1), and one Sn(2) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the fifth Se site, Se(5) is bonded to two equivalent Cu(1), one Zn(2), and one Sn(3) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(5)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, corners with three equivalent Se(10)FeCu2Sn tetrahedra, and corners with three equivalent Se(7)ZnCu2Sn tetrahedra. In the sixth Se site, Se(6) is bonded to two equivalent Cu(3), one Zn(1), and one Sn(1) atom to form corner-sharing SeZnCu2Sn tetrahedra. In the seventh Se site, Se(7) is bonded to one Cu(1), one Cu(5), one Zn(2), and one Sn(1) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(6)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(10)FeCu2Sn tetrahedra, corners with two equivalent Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, and corners with three equivalent Se(5)ZnCu2Sn tetrahedra. In the eighth Se site, Se(8) is bonded to one Cu(2), one Cu(4), one Zn(2), and one Sn(3) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(2)ZnCu2Sn tetrahedra,  a cornercorner with one Se(4)ZnCu2Sn tetrahedra,  a cornercorner with one Se(7)ZnCu2Sn tetrahedra, corners with two equivalent Se(3)FeCu2Sn tetrahedra, corners with two equivalent Se(1)ZnCu2Sn tetrahedra, corners with two equivalent Se(5)ZnCu2Sn tetrahedra, and corners with two equivalent Se(9)ZnCu2Sn tetrahedra. In the ninth Se site, Se(9) is bonded to one Cu(2), one Cu(4), one Zn(1), and one Sn(2) atom to form SeZnCu2Sn tetrahedra that share  a cornercorner with one Se(3)FeCu2Sn tetrahedra,  a cornercorner with one Se(1)ZnCu2Sn tetrahedra,  a cornercorner with one Se(6)ZnCu2Sn tetrahedra,  a cornercorner with one Se(9)ZnCu2Sn tetrahedra, corners with two equivalent Se(2)ZnCu2Sn tetrahedra, corners with two equivalent Se(8)ZnCu2Sn tetrahedra, and corners with four equivalent Se(4)ZnCu2Sn tetrahedra. In the tenth Se site, Se(10) is bonded to one Fe(1), one Cu(1), one Cu(5), and one Sn(3) atom to form SeFeCu2Sn tetrahedra that share  a cornercorner with one Se(10)FeCu2Sn tetrahedra,  a cornercorner with one Se(2)ZnCu2Sn tetrahedra,  a cornercorner with one Se(8)ZnCu2Sn tetrahedra, corners with two equivalent Se(7)ZnCu2Sn tetrahedra, corners with three equivalent Se(5)ZnCu2Sn tetrahedra, and corners with four equivalent Se(3)FeCu2Sn tetrahedra.