DOI: 10.17188/1666441
title: Materials Data on K4U5B2O21 by Materials Project

description: K4U5B2O21 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are four inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to six O atoms. There are a spread of K–O bond distances ranging from 2.80–2.90 Å. In the second K site, K is bonded to six O atoms to form distorted KO6 pentagonal pyramids that share corners with two equivalent UO6 octahedra and corners with four UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of K–O bond distances ranging from 2.79–2.91 Å. In the third K site, K is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of K–O bond distances ranging from 2.67–3.33 Å. In the fourth K site, K is bonded in a 6-coordinate geometry to six O atoms. There are a spread of K–O bond distances ranging from 2.67–3.28 Å. There are five inequivalent U sites. In the first U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO7 pentagonal bipyramid, corners with two equivalent KO6 pentagonal pyramids, an edgeedge with one UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. There are a spread of U–O bond distances ranging from 1.85–2.40 Å. In the second U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO7 pentagonal bipyramid, an edgeedge with one UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. There are a spread of U–O bond distances ranging from 1.85–2.40 Å. In the third U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO6 octahedra, a cornercorner with one UO7 pentagonal bipyramid, corners with two equivalent KO6 pentagonal pyramids, and edges with three UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 46°. There are a spread of U–O bond distances ranging from 1.86–2.48 Å. In the fourth U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO6 octahedra, a cornercorner with one UO7 pentagonal bipyramid, and edges with three UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 46°. There are a spread of U–O bond distances ranging from 1.85–2.48 Å. In the fifth U site, U is bonded to six O atoms to form distorted UO6 octahedra that share corners with two UO7 pentagonal bipyramids, corners with two equivalent KO6 pentagonal pyramids, and edges with two UO7 pentagonal bipyramids. There are a spread of U–O bond distances ranging from 1.86–2.31 Å. There are two inequivalent B sites. In the first B site, B is bonded in a trigonal planar geometry to three O atoms. There is two shorter (1.37 Å) and one longer (1.38 Å) B–O bond length. In the second B site, B is bonded in a trigonal planar geometry to three O atoms. There is two shorter (1.37 Å) and one longer (1.38 Å) B–O bond length. There are twenty-one inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to three K and one U atom. In the second O site, O is bonded in a distorted single-bond geometry to three K and one U atom. In the third O site, O is bonded in a distorted trigonal planar geometry to two U and one B atom. In the fourth O site, O is bonded in a 1-coordinate geometry to two U and one B atom. In the fifth O site, O is bonded in a 1-coordinate geometry to two U and one B atom. In the sixth O site, O is bonded in a distorted single-bond geometry to two U and one B atom. In the seventh O site, O is bonded in a distorted trigonal planar geometry to three U atoms. In the eighth O site, O is bonded in a distorted trigonal planar geometry to three U atoms. In the ninth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the tenth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the eleventh O site, O is bonded in a trigonal planar geometry to three U atoms. In the twelfth O site, O is bonded in a trigonal planar geometry to three U atoms. In the thirteenth O site, O is bonded in a distorted single-bond geometry to three K and one U atom. In the fourteenth O site, O is bonded in a distorted single-bond geometry to three K and one U atom. In the fifteenth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the sixteenth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the seventeenth O site, O is bonded in a distorted single-bond geometry to two U and one B atom. In the eighteenth O site, O is bonded in a distorted single-bond geometry to two U and one B atom. In the nineteenth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the twentieth O site, O is bonded in a distorted single-bond geometry to two K and one U atom. In the twenty-first O site, O is bonded in a single-bond geometry to one K atom.