UNi10Si2 crystallizes in the orthorhombic Immm space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), eight equivalent Ni(4), and four equivalent Si(1) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 8-coordinate geometry to one U(1), one Ni(1), two equivalent Ni(3), four equivalent Ni(2), four equivalent Ni(4), and two equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded in a 14-coordinate geometry to one U(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), four equivalent Ni(4), and two equivalent Si(1) atoms. In the third Ni site, Ni(3) is bonded in a 13-coordinate geometry to two equivalent U(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(4), and two equivalent Si(1) atoms. In the fourth Ni site, Ni(4) is bonded to two equivalent U(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), two equivalent Ni(4), and two equivalent Si(1) atoms to form distorted NiU2Si2Ni8 cuboctahedra that share corners with four equivalent Si(1)U2Ni10 cuboctahedra, corners with ten equivalent Ni(4)U2Si2Ni8 cuboctahedra, edges with two equivalent Si(1)U2Ni10 cuboctahedra, edges with four equivalent Ni(4)U2Si2Ni8 cuboctahedra, faces with four equivalent Si(1)U2Ni10 cuboctahedra, and faces with six equivalent Ni(4)U2Si2Ni8 cuboctahedra. Si(1) is bonded to two equivalent U(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms to form distorted SiU2Ni10 cuboctahedra that share corners with six equivalent Si(1)U2Ni10 cuboctahedra, corners with eight equivalent Ni(4)U2Si2Ni8 cuboctahedra, edges with three equivalent Si(1)U2Ni10 cuboctahedra, edges with four equivalent Ni(4)U2Si2Ni8 cuboctahedra,  a faceface with one Si(1)U2Ni10 cuboctahedra, and faces with eight equivalent Ni(4)U2Si2Ni8 cuboctahedra.
UNi10Si2 crystallizes in the orthorhombic Immm space group. U(1) is bonded in a 8-coordinate geometry to two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(3), eight equivalent Ni(4), and four equivalent Si(1) atoms. Both U(1)-Ni(1) bond lengths are 2.91 Å. Both U(1)-Ni(2) bond lengths are 2.67 Å. All U(1)-Ni(3) bond lengths are 2.78 Å. All U(1)-Ni(4) bond lengths are 3.09 Å. All U(1)-Si(1) bond lengths are 3.16 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 8-coordinate geometry to one U(1), one Ni(1), two equivalent Ni(3), four equivalent Ni(2), four equivalent Ni(4), and two equivalent Si(1) atoms. The Ni(1)-Ni(1) bond length is 2.42 Å. Both Ni(1)-Ni(3) bond lengths are 2.79 Å. All Ni(1)-Ni(2) bond lengths are 2.96 Å. All Ni(1)-Ni(4) bond lengths are 2.45 Å. Both Ni(1)-Si(1) bond lengths are 2.54 Å. In the second Ni site, Ni(2) is bonded in a 14-coordinate geometry to one U(1), one Ni(2), two equivalent Ni(3), four equivalent Ni(1), four equivalent Ni(4), and two equivalent Si(1) atoms. The Ni(2)-Ni(2) bond length is 2.51 Å. Both Ni(2)-Ni(3) bond lengths are 2.71 Å. All Ni(2)-Ni(4) bond lengths are 2.48 Å. Both Ni(2)-Si(1) bond lengths are 2.40 Å. In the third Ni site, Ni(3) is bonded in a 13-coordinate geometry to two equivalent U(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), four equivalent Ni(4), and two equivalent Si(1) atoms. The Ni(3)-Ni(3) bond length is 2.83 Å. All Ni(3)-Ni(4) bond lengths are 2.44 Å. Both Ni(3)-Si(1) bond lengths are 2.50 Å. In the fourth Ni site, Ni(4) is bonded to two equivalent U(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), two equivalent Ni(4), and two equivalent Si(1) atoms to form distorted NiU2Si2Ni8 cuboctahedra that share corners with four equivalent Si(1)U2Ni10 cuboctahedra, corners with ten equivalent Ni(4)U2Si2Ni8 cuboctahedra, edges with two equivalent Si(1)U2Ni10 cuboctahedra, edges with four equivalent Ni(4)U2Si2Ni8 cuboctahedra, faces with four equivalent Si(1)U2Ni10 cuboctahedra, and faces with six equivalent Ni(4)U2Si2Ni8 cuboctahedra. Both Ni(4)-Ni(4) bond lengths are 2.40 Å. Both Ni(4)-Si(1) bond lengths are 2.30 Å. Si(1) is bonded to two equivalent U(1), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms to form distorted SiU2Ni10 cuboctahedra that share corners with six equivalent Si(1)U2Ni10 cuboctahedra, corners with eight equivalent Ni(4)U2Si2Ni8 cuboctahedra, edges with three equivalent Si(1)U2Ni10 cuboctahedra, edges with four equivalent Ni(4)U2Si2Ni8 cuboctahedra,  a faceface with one Si(1)U2Ni10 cuboctahedra, and faces with eight equivalent Ni(4)U2Si2Ni8 cuboctahedra.