Materials Data on Sm2Zr2O7 by Materials Project

Abstract

Sm2Zr2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sm–O bond distances ranging from 2.28–2.73 Å. In the second Sm3+ site, Sm3+ is bonded to six O2- atoms to form distorted SmO6 pentagonal pyramids that share corners with three equivalent ZrO6 pentagonal pyramids, corners with two equivalent ZrO5 trigonal bipyramids, an edgeedge with one ZrO6 pentagonal pyramid, and an edgeedge with one ZrO5 trigonal bipyramid. There are a spread of Sm–O bond distances ranging from 2.30–2.45 Å. There are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to five O2- atoms to form distorted ZrO5 trigonal bipyramids that share corners with two equivalent SmO6 pentagonal pyramids, corners with two equivalent ZrO6 pentagonal pyramids, an edgeedge with one SmO6 pentagonal pyramid, and an edgeedge with one ZrO6 pentagonal pyramid. There are a spread of Zr–O bond distances ranging from 2.01–2.20 Å. In the second Zr4+ site, Zr4+ is bonded to six O2- atoms to form distorted ZrO6 pentagonal pyramids that share corners with three equivalent SmO6 pentagonal pyramids, corners with two equivalent ZrO5 trigonal bipyramids, an edgeedge with one SmO6 pentagonal pyramid, an edgeedge with one ZrO6 pentagonal pyramid, and an edgeedge with one ZrO5 trigonal bipyramid. There are a spread of Zr–O bond distances ranging from 2.02–2.29 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to one Sm3+ and three Zr4+ atoms to form distorted OSmZr3 trigonal pyramids that share corners with two equivalent OSm3Zr tetrahedra, a cornercorner with one OSm3Zr trigonal pyramid, and edges with two OSmZr3 trigonal pyramids. In the second O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form distorted OSm3Zr tetrahedra that share corners with two equivalent OSm3Zr tetrahedra, corners with five OSmZr3 trigonal pyramids, and an edgeedge with one OSm3Zr trigonal pyramid. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Sm3+ and one Zr4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sm3+ and two Zr4+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Sm3+ and one Zr4+ atom. In the sixth O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form distorted OSm3Zr trigonal pyramids that share corners with three equivalent OSm3Zr tetrahedra, a cornercorner with one OSmZr3 trigonal pyramid, an edgeedge with one OSm3Zr tetrahedra, and edges with two OSmZr3 trigonal pyramids. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Sm3+ and two Zr4+ atoms.