Materials Data on KEu2I5 by Materials Project

Abstract

KEu2I5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of K–I bond distances ranging from 3.62–4.06 Å. There are two inequivalent Eu2+ sites. In the first Eu2+ site, Eu2+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Eu–I bond distances ranging from 3.39–3.58 Å. In the second Eu2+ site, Eu2+ is bonded to seven I1- atoms to form distorted edge-sharing EuI7 pentagonal bipyramids. There are a spread of Eu–I bond distances ranging from 3.24–3.47 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded to two equivalent K1+ and three Eu2+ atoms to form distorted IK2Eu3 trigonal bipyramids that share corners with four equivalent IK2Eu3 square pyramids, corners with two equivalent IEu4 tetrahedra, corners with four equivalent IK2Eu3 trigonal bipyramids, corners with two equivalent IK2Eu2 trigonal pyramids, an edgeedge with one IK2Eu3 square pyramid, edges with two equivalent IEu4 tetrahedra, edges with two equivalent IK2Eu2 trigonal pyramids, and a faceface with one IK2Eu3 square pyramid. In the second I1- site, I1- is bonded in a 5-coordinate geometry to two equivalent K1+ and three Eu2+ atoms. In the third I1- site, I1- is bonded to two equivalent K1+ and three Eu2+ atoms to form distorted IK2Eu3 square pyramids that share corners with four equivalent IEu4 tetrahedra, corners with four equivalent IK2Eu3 trigonal bipyramids, corners with four equivalent IK2Eu2 trigonal pyramids, edges with two equivalent IK2Eu3 square pyramids, an edgeedge with one IEu4 tetrahedra, an edgeedge with one IK2Eu3 trigonal bipyramid, an edgeedge with one IK2Eu2 trigonal pyramid, and a faceface with one IK2Eu3 trigonal bipyramid. In the fourth I1- site, I1- is bonded to four Eu2+ atoms to form distorted IEu4 tetrahedra that share corners with four equivalent IK2Eu3 square pyramids, corners with two equivalent IEu4 tetrahedra, corners with two equivalent IK2Eu3 trigonal bipyramids, corners with four equivalent IK2Eu2 trigonal pyramids, an edgeedge with one IK2Eu3 square pyramid, an edgeedge with one IEu4 tetrahedra, and edges with two equivalent IK2Eu3 trigonal bipyramids. In the fifth I1- site, I1- is bonded to two equivalent K1+ and two equivalent Eu2+ atoms to form distorted IK2Eu2 trigonal pyramids that share corners with four equivalent IK2Eu3 square pyramids, corners with four equivalent IEu4 tetrahedra, corners with two equivalent IK2Eu3 trigonal bipyramids, corners with two equivalent IK2Eu2 trigonal pyramids, an edgeedge with one IK2Eu3 square pyramid, edges with two equivalent IK2Eu3 trigonal bipyramids, and an edgeedge with one IK2Eu2 trigonal pyramid.