Materials Data on U2Si5Tc3 by Materials Project
U2Tc3Si5 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. U+5.50+ is bonded in a 11-coordinate geometry to four Tc+2.33- and nine Si+0.80- atoms. There are two shorter (3.09 Å) and two longer (3.30 Å) U–Tc bond lengths. There are a spread of U–Si bond distances ranging from 2.89–3.19 Å. There are two inequivalent Tc+2.33- sites. In the first Tc+2.33- site, Tc+2.33- is bonded in a 8-coordinate geometry to two equivalent U+5.50+ and six Si+0.80- atoms. There are a spread of Tc–Si bond distances ranging from 2.45–2.53 Å. In the second Tc+2.33- site, Tc+2.33- is bonded to four equivalent U+5.50+, two equivalent Tc+2.33-, and six Si+0.80- atoms to form a mixture of distorted corner and face-sharing TcU4Si6Tc2 cuboctahedra. Both Tc–Tc bond lengths are 2.74 Å. There are four shorter (2.45 Å) and two longer (2.69 Å) Tc–Si bond lengths. There are three inequivalent Si+0.80- sites. In the first Si+0.80- site, Si+0.80- is bonded in a 9-coordinate geometry to four equivalent U+5.50+, four equivalent Tc+2.33-, and one Si+0.80- atom. The Si–Si bond length is 2.57 Å. In the second Si+0.80- site, Si+0.80- is bonded in a 11-coordinate geometry to four equivalent U+5.50+, three Tc+2.33-, and four Si+0.80- atoms. There are two shorter (2.57 Å) and two longer (2.74 Å) Si–Si bond lengths. In the third Si+0.80- site, Si+0.80- is bonded in a 9-coordinate geometry to three equivalent U+5.50+, four Tc+2.33-, and two equivalent Si+0.80- atoms.