Y2RhSi3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to twelve equivalent Si(1) atoms to form YSi12 cuboctahedra that share edges with twelve equivalent Y(2)Si8Rh4 cuboctahedra, faces with two equivalent Y(1)Si12 cuboctahedra, and faces with six equivalent Y(2)Si8Rh4 cuboctahedra. In the second Y site, Y(2) is bonded to four equivalent Rh(1) and eight equivalent Si(1) atoms to form YSi8Rh4 cuboctahedra that share edges with four equivalent Y(1)Si12 cuboctahedra, edges with eight equivalent Y(2)Si8Rh4 cuboctahedra, faces with two equivalent Y(1)Si12 cuboctahedra, and faces with six equivalent Y(2)Si8Rh4 cuboctahedra. Rh(1) is bonded in a 9-coordinate geometry to six equivalent Y(2) and three equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent Y(1), four equivalent Y(2), one Rh(1), and two equivalent Si(1) atoms.
Y2RhSi3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to twelve equivalent Si(1) atoms to form YSi12 cuboctahedra that share edges with twelve equivalent Y(2)Si8Rh4 cuboctahedra, faces with two equivalent Y(1)Si12 cuboctahedra, and faces with six equivalent Y(2)Si8Rh4 cuboctahedra. There are six shorter (3.08 Å) and six longer (3.09 Å) Y(1)-Si(1) bond lengths. In the second Y site, Y(2) is bonded to four equivalent Rh(1) and eight equivalent Si(1) atoms to form YSi8Rh4 cuboctahedra that share edges with four equivalent Y(1)Si12 cuboctahedra, edges with eight equivalent Y(2)Si8Rh4 cuboctahedra, faces with two equivalent Y(1)Si12 cuboctahedra, and faces with six equivalent Y(2)Si8Rh4 cuboctahedra. There are two shorter (3.06 Å) and two longer (3.12 Å) Y(2)-Rh(1) bond lengths. There are four shorter (3.08 Å) and four longer (3.11 Å) Y(2)-Si(1) bond lengths. Rh(1) is bonded in a 9-coordinate geometry to six equivalent Y(2) and three equivalent Si(1) atoms. All Rh(1)-Si(1) bond lengths are 2.37 Å. Si(1) is bonded in a 9-coordinate geometry to two equivalent Y(1), four equivalent Y(2), one Rh(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.36 Å.