Materials Data on USi3Ni2 by Materials Project
UNi2Si3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. U6+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are four shorter (2.96 Å) and four longer (3.06 Å) U–Si bond lengths. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing NiSi4 tetrahedra. All Ni–Si bond lengths are 2.32 Å. In the second Ni3+ site, Ni3+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are four shorter (2.27 Å) and one longer (2.29 Å) Ni–Si bond lengths. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 3-coordinate geometry to two equivalent U6+, two equivalent Ni3+, and five equivalent Si4- atoms. There are one shorter (2.34 Å) and four longer (2.75 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent U6+ and five Ni3+ atoms.