Y3Fe2Si3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 9-coordinate geometry to four equivalent Fe(1), two equivalent Si(2), and three equivalent Si(1) atoms. In the second Y site, Y(2) is bonded in a 10-coordinate geometry to four equivalent Fe(1), two equivalent Si(1), and four equivalent Si(2) atoms. Fe(1) is bonded in a 10-coordinate geometry to two equivalent Y(1), four equivalent Y(2), one Si(1), and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Y(1), four equivalent Y(2), and two equivalent Fe(1) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Y(1), four equivalent Y(2), and three equivalent Fe(1) atoms.
Y3Fe2Si3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 9-coordinate geometry to four equivalent Fe(1), two equivalent Si(2), and three equivalent Si(1) atoms. All Y(1)-Fe(1) bond lengths are 3.20 Å. Both Y(1)-Si(2) bond lengths are 2.87 Å. There are two shorter (2.86 Å) and one longer (3.30 Å) Y(1)-Si(1) bond length. In the second Y site, Y(2) is bonded in a 10-coordinate geometry to four equivalent Fe(1), two equivalent Si(1), and four equivalent Si(2) atoms. There are a spread of Y(2)-Fe(1) bond distances ranging from 3.00-3.15 Å. Both Y(2)-Si(1) bond lengths are 2.95 Å. There are two shorter (2.96 Å) and two longer (3.15 Å) Y(2)-Si(2) bond lengths. Fe(1) is bonded in a 10-coordinate geometry to two equivalent Y(1), four equivalent Y(2), one Si(1), and three equivalent Si(2) atoms. The Fe(1)-Si(1) bond length is 2.59 Å. There are two shorter (2.31 Å) and one longer (2.34 Å) Fe(1)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Y(1), four equivalent Y(2), and two equivalent Fe(1) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Y(1), four equivalent Y(2), and three equivalent Fe(1) atoms.