U2RuSi3 crystallizes in the trigonal P-3m1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to twelve equivalent Si(1) atoms to form USi12 cuboctahedra that share edges with twelve equivalent U(2)Si8Ru4 cuboctahedra, faces with two equivalent U(1)Si12 cuboctahedra, and faces with six equivalent U(2)Si8Ru4 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Ru(1) and eight equivalent Si(1) atoms to form USi8Ru4 cuboctahedra that share edges with four equivalent U(1)Si12 cuboctahedra, edges with eight equivalent U(2)Si8Ru4 cuboctahedra, faces with two equivalent U(1)Si12 cuboctahedra, and faces with six equivalent U(2)Si8Ru4 cuboctahedra. Ru(1) is bonded in a 9-coordinate geometry to six equivalent U(2) and three equivalent Si(1) atoms. Si(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Ru(1), and two equivalent Si(1) atoms.
U2RuSi3 crystallizes in the trigonal P-3m1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to twelve equivalent Si(1) atoms to form USi12 cuboctahedra that share edges with twelve equivalent U(2)Si8Ru4 cuboctahedra, faces with two equivalent U(1)Si12 cuboctahedra, and faces with six equivalent U(2)Si8Ru4 cuboctahedra. There are six shorter (2.98 Å) and six longer (3.02 Å) U(1)-Si(1) bond lengths. In the second U site, U(2) is bonded to four equivalent Ru(1) and eight equivalent Si(1) atoms to form USi8Ru4 cuboctahedra that share edges with four equivalent U(1)Si12 cuboctahedra, edges with eight equivalent U(2)Si8Ru4 cuboctahedra, faces with two equivalent U(1)Si12 cuboctahedra, and faces with six equivalent U(2)Si8Ru4 cuboctahedra. There are two shorter (2.97 Å) and two longer (3.10 Å) U(2)-Ru(1) bond lengths. There are four shorter (3.02 Å) and four longer (3.07 Å) U(2)-Si(1) bond lengths. Ru(1) is bonded in a 9-coordinate geometry to six equivalent U(2) and three equivalent Si(1) atoms. All Ru(1)-Si(1) bond lengths are 2.41 Å. Si(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Ru(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.33 Å.