Cu2ZnSiSe4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. Cu(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Zn(1)Se4 tetrahedra, and corners with four equivalent Si(1)Se4 tetrahedra. Zn(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form ZnSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. Si(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form SiSe4 tetrahedra that share corners with four equivalent Zn(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra. In the second Se site, Se(2) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra. In the third Se site, Se(3) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra.
Cu2ZnSiSe4 is Stannite-like structured and crystallizes in the orthorhombic Pmn2_1 space group. Cu(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Zn(1)Se4 tetrahedra, and corners with four equivalent Si(1)Se4 tetrahedra. The Cu(1)-Se(1) bond length is 2.42 Å. The Cu(1)-Se(2) bond length is 2.42 Å. There is one shorter (2.42 Å) and one longer (2.45 Å) Cu(1)-Se(3) bond length. Zn(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form ZnSe4 tetrahedra that share corners with four equivalent Si(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. The Zn(1)-Se(1) bond length is 2.49 Å. The Zn(1)-Se(2) bond length is 2.46 Å. Both Zn(1)-Se(3) bond lengths are 2.53 Å. Si(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form SiSe4 tetrahedra that share corners with four equivalent Zn(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. The Si(1)-Se(1) bond length is 2.32 Å. The Si(1)-Se(2) bond length is 2.33 Å. Both Si(1)-Se(3) bond lengths are 2.34 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra. In the second Se site, Se(2) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra. In the third Se site, Se(3) is bonded to two equivalent Cu(1), one Zn(1), and one Si(1) atom to form corner-sharing SeZnCu2Si tetrahedra.