UMnFeSi2 crystallizes in the tetragonal I-4m2 space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Mn(1), four equivalent Fe(1), and eight equivalent Si(1) atoms. Mn(1) is bonded to four equivalent U(1), four equivalent Fe(1), and four equivalent Si(1) atoms to form distorted MnU4Fe4Si4 tetrahedra that share corners with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, corners with twelve equivalent Mn(1)U4Fe4Si4 tetrahedra, edges with two equivalent Fe(1)U4Mn4Si4 cuboctahedra, faces with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)U4Fe4Si4 tetrahedra. Fe(1) is bonded to four equivalent U(1), four equivalent Mn(1), and four equivalent Si(1) atoms to form distorted FeU4Mn4Si4 cuboctahedra that share corners with twelve equivalent Fe(1)U4Mn4Si4 cuboctahedra, corners with four equivalent Mn(1)U4Fe4Si4 tetrahedra, edges with two equivalent Mn(1)U4Fe4Si4 tetrahedra, faces with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)U4Fe4Si4 tetrahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent U(1), two equivalent Mn(1), two equivalent Fe(1), and one Si(1) atom.
UMnFeSi2 crystallizes in the tetragonal I-4m2 space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Mn(1), four equivalent Fe(1), and eight equivalent Si(1) atoms. All U(1)-Mn(1) bond lengths are 3.04 Å. All U(1)-Fe(1) bond lengths are 3.04 Å. All U(1)-Si(1) bond lengths are 3.06 Å. Mn(1) is bonded to four equivalent U(1), four equivalent Fe(1), and four equivalent Si(1) atoms to form distorted MnU4Fe4Si4 tetrahedra that share corners with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, corners with twelve equivalent Mn(1)U4Fe4Si4 tetrahedra, edges with two equivalent Fe(1)U4Mn4Si4 cuboctahedra, faces with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)U4Fe4Si4 tetrahedra. All Mn(1)-Fe(1) bond lengths are 2.82 Å. All Mn(1)-Si(1) bond lengths are 2.28 Å. Fe(1) is bonded to four equivalent U(1), four equivalent Mn(1), and four equivalent Si(1) atoms to form distorted FeU4Mn4Si4 cuboctahedra that share corners with twelve equivalent Fe(1)U4Mn4Si4 cuboctahedra, corners with four equivalent Mn(1)U4Fe4Si4 tetrahedra, edges with two equivalent Mn(1)U4Fe4Si4 tetrahedra, faces with four equivalent Fe(1)U4Mn4Si4 cuboctahedra, and faces with four equivalent Mn(1)U4Fe4Si4 tetrahedra. All Fe(1)-Si(1) bond lengths are 2.28 Å. Si(1) is bonded in a 9-coordinate geometry to four equivalent U(1), two equivalent Mn(1), two equivalent Fe(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.39 Å.