DOI: 10.17188/1710516
title: Materials Data on K4UC2Se2O15 by Materials Project

description: K4UC2Se2O15 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.24 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.74–3.11 Å. In the third K1+ site, K1+ is bonded to seven O2- atoms to form distorted KO7 pentagonal bipyramids that share a cornercorner with one UO7 pentagonal bipyramid, corners with two equivalent KO7 pentagonal bipyramids, corners with two equivalent SeO4 tetrahedra, and an edgeedge with one SeO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.77–3.12 Å. In the fourth K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.21 Å. U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one KO7 pentagonal bipyramid and corners with three SeO4 tetrahedra. There are a spread of U–O bond distances ranging from 1.82–2.42 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.29 Å) C–O bond length. In the second C4+ site, C4+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.25 Å) and one longer (1.29 Å) C–O bond length. There are two inequivalent Se6+ sites. In the first Se6+ site, Se6+ is bonded to four O2- atoms to form SeO4 tetrahedra that share a cornercorner with one UO7 pentagonal bipyramid, corners with two equivalent KO7 pentagonal bipyramids, and an edgeedge with one KO7 pentagonal bipyramid. There are a spread of Se–O bond distances ranging from 1.66–1.73 Å. In the second Se6+ site, Se6+ is bonded to four O2- atoms to form SeO4 tetrahedra that share corners with two equivalent UO7 pentagonal bipyramids. There are a spread of Se–O bond distances ranging from 1.65–1.70 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one U6+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one U6+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and one Se6+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one Se6+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+, one U6+, and one Se6+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one Se6+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one Se6+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two K1+ and one Se6+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one U6+, and one Se6+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one U6+, and one Se6+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one U6+, and one C4+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one U6+, and one C4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one C4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one C4+ atom. In the fifteenth O2- site, O2- is bonded in a distorted L-shaped geometry to two K1+ atoms.