Materials Data on U2Ti3Si4 by Materials Project
U2Ti3Si4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. U3+ is bonded in a 8-coordinate geometry to one U3+ and seven Si4- atoms. The U–U bond length is 2.65 Å. There are a spread of U–Si bond distances ranging from 2.75–3.01 Å. There are two inequivalent Ti+3.33+ sites. In the first Ti+3.33+ site, Ti+3.33+ is bonded to six Si4- atoms to form a mixture of distorted corner, edge, and face-sharing TiSi6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 33–44°. There are a spread of Ti–Si bond distances ranging from 2.56–2.71 Å. In the second Ti+3.33+ site, Ti+3.33+ is bonded to six Si4- atoms to form a mixture of corner and face-sharing TiSi6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are four shorter (2.67 Å) and two longer (2.74 Å) Ti–Si bond lengths. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to three equivalent U3+, five Ti+3.33+, and one Si4- atom. The Si–Si bond length is 2.61 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent U3+, four Ti+3.33+, and one Si4- atom. The Si–Si bond length is 2.40 Å.