Dy2Si3 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. In the second Dy site, Dy(2) is bonded in a 10-coordinate geometry to two equivalent Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to two equivalent Dy(1), four equivalent Dy(2), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Dy(2), four equivalent Dy(1), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Dy(1), four equivalent Dy(2), one Si(1), and two equivalent Si(2) atoms.
Dy2Si3 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. Both Dy(1)-Si(1) bond lengths are 2.92 Å. Both Dy(1)-Si(3) bond lengths are 3.09 Å. All Dy(1)-Si(2) bond lengths are 2.96 Å. In the second Dy site, Dy(2) is bonded in a 10-coordinate geometry to two equivalent Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. Both Dy(2)-Si(2) bond lengths are 3.12 Å. All Dy(2)-Si(1) bond lengths are 3.08 Å. All Dy(2)-Si(3) bond lengths are 2.97 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to two equivalent Dy(1), four equivalent Dy(2), and one Si(3) atom. The Si(1)-Si(3) bond length is 2.33 Å. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Dy(2), four equivalent Dy(1), and two equivalent Si(3) atoms. Both Si(2)-Si(3) bond lengths are 2.38 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Dy(1), four equivalent Dy(2), one Si(1), and two equivalent Si(2) atoms.