Materials Data on USe3 by Materials Project
USe3 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one USe3 sheet oriented in the (0, 0, 1) direction. U6+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of U–Se bond distances ranging from 2.89–2.96 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent U6+ and one Se2- atom. The Se–Se bond length is 2.38 Å. In the second Se2- site, Se2- is bonded to four equivalent U6+ atoms to form a mixture of distorted edge and corner-sharing SeU4 trigonal pyramids. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent U6+ and one Se2- atom.