Materials Data on U2As3Se by Materials Project
U2As3Se crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. there are two inequivalent U+5.50+ sites. In the first U+5.50+ site, U+5.50+ is bonded in a 9-coordinate geometry to five As3- and four equivalent Se2- atoms. There are one shorter (2.95 Å) and four longer (3.04 Å) U–As bond lengths. All U–Se bond lengths are 2.89 Å. In the second U+5.50+ site, U+5.50+ is bonded in a 9-coordinate geometry to eight As3- and one Se2- atom. There are four shorter (2.89 Å) and four longer (3.02 Å) U–As bond lengths. The U–Se bond length is 2.94 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to four U+5.50+ and four equivalent As3- atoms. All As–As bond lengths are 2.81 Å. In the second As3- site, As3- is bonded to five U+5.50+ atoms to form distorted AsU5 trigonal bipyramids that share corners with four equivalent AsU5 trigonal bipyramids, edges with four equivalent AsU5 trigonal bipyramids, and edges with four equivalent SeU5 trigonal bipyramids. Se2- is bonded to five U+5.50+ atoms to form distorted SeU5 trigonal bipyramids that share corners with four equivalent SeU5 trigonal bipyramids, edges with four equivalent AsU5 trigonal bipyramids, and edges with four equivalent SeU5 trigonal bipyramids.