Sr2Zn5Si3 crystallizes in the tetragonal P4mm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 16-coordinate geometry to four equivalent Zn(1), four equivalent Zn(2), four equivalent Zn(3), and four equivalent Si(3) atoms. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to four equivalent Zn(1), four equivalent Zn(2), four equivalent Si(1), and four equivalent Si(2) atoms. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), two equivalent Zn(3), and two equivalent Si(2) atoms. In the second Zn site, Zn(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Si(1), and two equivalent Si(3) atoms to form a mixture of distorted face and edge-sharing ZnSr4Si4 tetrahedra. In the third Zn site, Zn(3) is bonded in a distorted single-bond geometry to four equivalent Sr(1), four equivalent Zn(1), and one Si(3) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Sr(2), four equivalent Zn(2), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), four equivalent Zn(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Zn(3), and four equivalent Zn(2) atoms.
Sr2Zn5Si3 crystallizes in the tetragonal P4mm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 16-coordinate geometry to four equivalent Zn(1), four equivalent Zn(2), four equivalent Zn(3), and four equivalent Si(3) atoms. All Sr(1)-Zn(1) bond lengths are 3.47 Å. All Sr(1)-Zn(2) bond lengths are 3.38 Å. All Sr(1)-Zn(3) bond lengths are 3.26 Å. All Sr(1)-Si(3) bond lengths are 3.24 Å. In the second Sr site, Sr(2) is bonded in a 16-coordinate geometry to four equivalent Zn(1), four equivalent Zn(2), four equivalent Si(1), and four equivalent Si(2) atoms. All Sr(2)-Zn(1) bond lengths are 3.40 Å. All Sr(2)-Zn(2) bond lengths are 3.35 Å. All Sr(2)-Si(1) bond lengths are 3.22 Å. All Sr(2)-Si(2) bond lengths are 3.24 Å. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), two equivalent Zn(3), and two equivalent Si(2) atoms. Both Zn(1)-Zn(3) bond lengths are 2.58 Å. Both Zn(1)-Si(2) bond lengths are 2.55 Å. In the second Zn site, Zn(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), two equivalent Si(1), and two equivalent Si(3) atoms to form a mixture of distorted face and edge-sharing ZnSr4Si4 tetrahedra. Both Zn(2)-Si(1) bond lengths are 2.55 Å. Both Zn(2)-Si(3) bond lengths are 2.55 Å. In the third Zn site, Zn(3) is bonded in a distorted single-bond geometry to four equivalent Sr(1), four equivalent Zn(1), and one Si(3) atom. The Zn(3)-Si(3) bond length is 2.50 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Sr(2), four equivalent Zn(2), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.41 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Sr(2), four equivalent Zn(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Zn(3), and four equivalent Zn(2) atoms.