Materials Data on U4Si6Tc7 by Materials Project
U4Tc7Si6 crystallizes in the cubic Im-3m space group. The structure is three-dimensional. U+3.25+ is bonded in a hexagonal planar geometry to six equivalent Tc3- atoms. All U–Tc bond lengths are 2.91 Å. There are two inequivalent Tc3- sites. In the first Tc3- site, Tc3- is bonded to four equivalent U+3.25+, four equivalent Tc3-, and four equivalent Si+1.33+ atoms to form distorted TcU4Si4Tc4 cuboctahedra that share corners with four equivalent TcU4Si4Tc4 cuboctahedra, corners with four equivalent TcSi6 octahedra, edges with eight equivalent TcU4Si4Tc4 cuboctahedra, and faces with six equivalent TcU4Si4Tc4 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. All Tc–Tc bond lengths are 2.91 Å. All Tc–Si bond lengths are 2.58 Å. In the second Tc3- site, Tc3- is bonded to six equivalent Si+1.33+ atoms to form corner-sharing TcSi6 octahedra. All Tc–Si bond lengths are 2.55 Å. Si+1.33+ is bonded in a 5-coordinate geometry to five Tc3- atoms.