U4Re7Si6 crystallizes in the cubic Im-3m space group. U(1) is bonded to six equivalent Re(1) and six equivalent Si(1) atoms to form URe6Si6 cuboctahedra that share corners with twelve equivalent U(1)Re6Si6 cuboctahedra, edges with twelve equivalent Re(1)U4Re4Si4 cuboctahedra, faces with six equivalent U(1)Re6Si6 cuboctahedra, faces with six equivalent Re(1)U4Re4Si4 cuboctahedra, and faces with two equivalent Re(2)Si6 octahedra. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to four equivalent U(1), four equivalent Re(1), and four equivalent Si(1) atoms to form distorted ReU4Re4Si4 cuboctahedra that share corners with four equivalent Re(1)U4Re4Si4 cuboctahedra, corners with four equivalent Re(2)Si6 octahedra, edges with eight equivalent U(1)Re6Si6 cuboctahedra, edges with eight equivalent Re(1)U4Re4Si4 cuboctahedra, faces with four equivalent U(1)Re6Si6 cuboctahedra, and faces with six equivalent Re(1)U4Re4Si4 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. In the second Re site, Re(2) is bonded to six equivalent Si(1) atoms to form ReSi6 octahedra that share corners with twenty-four equivalent Re(1)U4Re4Si4 cuboctahedra and faces with eight equivalent U(1)Re6Si6 cuboctahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent U(1), one Re(2), and four equivalent Re(1) atoms.
U4Re7Si6 crystallizes in the cubic Im-3m space group. U(1) is bonded to six equivalent Re(1) and six equivalent Si(1) atoms to form URe6Si6 cuboctahedra that share corners with twelve equivalent U(1)Re6Si6 cuboctahedra, edges with twelve equivalent Re(1)U4Re4Si4 cuboctahedra, faces with six equivalent U(1)Re6Si6 cuboctahedra, faces with six equivalent Re(1)U4Re4Si4 cuboctahedra, and faces with two equivalent Re(2)Si6 octahedra. All U(1)-Re(1) bond lengths are 2.91 Å. All U(1)-Si(1) bond lengths are 2.95 Å. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to four equivalent U(1), four equivalent Re(1), and four equivalent Si(1) atoms to form distorted ReU4Re4Si4 cuboctahedra that share corners with four equivalent Re(1)U4Re4Si4 cuboctahedra, corners with four equivalent Re(2)Si6 octahedra, edges with eight equivalent U(1)Re6Si6 cuboctahedra, edges with eight equivalent Re(1)U4Re4Si4 cuboctahedra, faces with four equivalent U(1)Re6Si6 cuboctahedra, and faces with six equivalent Re(1)U4Re4Si4 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. All Re(1)-Re(1) bond lengths are 2.91 Å. All Re(1)-Si(1) bond lengths are 2.58 Å. In the second Re site, Re(2) is bonded to six equivalent Si(1) atoms to form ReSi6 octahedra that share corners with twenty-four equivalent Re(1)U4Re4Si4 cuboctahedra and faces with eight equivalent U(1)Re6Si6 cuboctahedra. All Re(2)-Si(1) bond lengths are 2.56 Å. Si(1) is bonded in a 9-coordinate geometry to four equivalent U(1), one Re(2), and four equivalent Re(1) atoms.