Materials Data on Rb2U6Pd4Se17 by Materials Project
Rb2U6Pd4Se17 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. Rb1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.44–3.75 Å. There are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded to seven Se2- atoms to form a mixture of distorted face and corner-sharing USe7 pentagonal bipyramids. There are a spread of U–Se bond distances ranging from 2.80–2.94 Å. In the second U4+ site, U4+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (2.89 Å) and four longer (3.04 Å) U–Se bond lengths. Pd2+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are two shorter (2.50 Å) and two longer (2.51 Å) Pd–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one Rb1+, two U4+, and one Pd2+ atom to form distorted SeRbU2Pd trigonal pyramids that share corners with two equivalent SeRb2U4 octahedra, corners with six equivalent SeRbU2Pd trigonal pyramids, and an edgeedge with one SeRbU2Pd trigonal pyramid. The corner-sharing octahedra tilt angles range from 39–70°. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to one Rb1+, three U4+, and one Pd2+ atom. In the third Se2- site, Se2- is bonded to two equivalent Rb1+ and four equivalent U4+ atoms to form distorted corner-sharing SeRb2U4 octahedra.