DOI: 10.17188/1263221
title: Materials Data on Sm2Zr2O7 by Materials Project

description: Sm2Zr2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are seven inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded to seven O2- atoms to form SmO7 pentagonal bipyramids that share corners with four ZrO6 octahedra, edges with two equivalent ZrO6 octahedra, and edges with two equivalent ZrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 53–67°. There are a spread of Sm–O bond distances ranging from 2.27–2.52 Å. In the second Sm3+ site, Sm3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.39–2.90 Å. In the third Sm3+ site, Sm3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.24–2.63 Å. In the fourth Sm3+ site, Sm3+ is bonded to six O2- atoms to form distorted SmO6 octahedra that share corners with four equivalent ZrO6 octahedra, corners with two equivalent ZrO7 pentagonal bipyramids, and edges with two equivalent ZrO6 octahedra. The corner-sharing octahedral tilt angles are 67°. There are two shorter (2.35 Å) and four longer (2.43 Å) Sm–O bond lengths. In the fifth Sm3+ site, Sm3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.32–2.62 Å. In the sixth Sm3+ site, Sm3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.31–2.62 Å. In the seventh Sm3+ site, Sm3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.31–2.59 Å. There are eight inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six O2- atoms to form ZrO6 octahedra that share corners with five ZrO6 octahedra, a cornercorner with one SmO7 pentagonal bipyramid, and an edgeedge with one ZrO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Zr–O bond distances ranging from 2.08–2.15 Å. In the second Zr4+ site, Zr4+ is bonded to six O2- atoms to form ZrO6 octahedra that share corners with five ZrO6 octahedra and a cornercorner with one SmO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 51–52°. There are a spread of Zr–O bond distances ranging from 2.10–2.16 Å. In the third Zr4+ site, Zr4+ is bonded to six O2- atoms to form ZrO6 octahedra that share corners with two equivalent SmO6 octahedra, corners with four ZrO6 octahedra, corners with two equivalent ZrO7 pentagonal bipyramids, and edges with two equivalent SmO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–67°. There are two shorter (2.03 Å) and four longer (2.13 Å) Zr–O bond lengths. In the fourth Zr4+ site, Zr4+ is bonded to seven O2- atoms to form distorted ZrO7 pentagonal bipyramids that share a cornercorner with one SmO6 octahedra, corners with two equivalent ZrO6 octahedra, edges with two equivalent ZrO6 octahedra, and edges with two equivalent SmO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–57°. There are a spread of Zr–O bond distances ranging from 2.07–2.42 Å. In the fifth Zr4+ site, Zr4+ is bonded to six O2- atoms to form distorted ZrO6 octahedra that share corners with four equivalent ZrO6 octahedra, corners with two equivalent SmO7 pentagonal bipyramids, and edges with two equivalent SmO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are two shorter (2.08 Å) and four longer (2.19 Å) Zr–O bond lengths. In the sixth Zr4+ site, Zr4+ is bonded to six O2- atoms to form corner-sharing ZrO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Zr–O bond distances ranging from 2.11–2.13 Å. In the seventh Zr4+ site, Zr4+ is bonded to six O2- atoms to form corner-sharing ZrO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are two shorter (2.11 Å) and four longer (2.12 Å) Zr–O bond lengths. In the eighth Zr4+ site, Zr4+ is bonded to six O2- atoms to form corner-sharing ZrO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are two shorter (2.11 Å) and four longer (2.12 Å) Zr–O bond lengths. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded to two Sm3+ and two Zr4+ atoms to form distorted OSm2Zr2 tetrahedra that share corners with six OSm2Zr2 tetrahedra and edges with four OSmZr3 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Sm3+ and two equivalent Zr4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Sm3+ and two Zr4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Sm3+ and two Zr4+ atoms. In the fifth O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form OSm3Zr tetrahedra that share corners with nine OSm2Zr2 tetrahedra and edges with three OSm3Zr tetrahedra. In the sixth O2- site, O2- is bonded to one Sm3+ and three Zr4+ atoms to form distorted OSmZr3 tetrahedra that share corners with six OSm4 tetrahedra and edges with three OSm2Zr2 tetrahedra. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Sm3+ and two equivalent Zr4+ atoms. In the eighth O2- site, O2- is bonded to two Sm3+ and two Zr4+ atoms to form distorted OSm2Zr2 tetrahedra that share corners with seven OSmZr3 tetrahedra and edges with three OSm2Zr2 tetrahedra. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Sm3+ and two Zr4+ atoms. In the tenth O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form OSm3Zr tetrahedra that share corners with ten OSm2Zr2 tetrahedra and edges with four OSm3Zr tetrahedra. In the eleventh O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form OSm3Zr tetrahedra that share corners with eight OSm3Zr tetrahedra and edges with three OSm2Zr2 tetrahedra. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to two Sm3+ and two Zr4+ atoms. In the thirteenth O2- site, O2- is bonded to three Sm3+ and one Zr4+ atom to form OSm3Zr tetrahedra that share corners with nine OSmZr3 tetrahedra and edges with three OSm2Zr2 tetrahedra. In the fourteenth O2- site, O2- is bonded to two Sm3+ and two Zr4+ atoms to form a mixture of distorted edge and corner-sharing OSm2Zr2 tetrahedra. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+ and two Zr4+ atoms. In the sixteenth O2- site, O2- is bonded to two Sm3+ and two equivalent Zr4+ atoms to form a mixture of distorted edge and corner-sharing OSm2Zr2 tetrahedra. In the seventeenth O2- site, O2- is bonded to two Sm3+ and two Zr4+ atoms to form a mixture of distorted edge and corner-sharing OSm2Zr2 tetrahedra. In the eighteenth O2- site, O2- is bonded to four Sm3+ atoms to form a mixture of edge and corner-sharing OSm4 tetrahedra. In the nineteenth O2- site, O2- is bonded to two equivalent Sm3+ and two Zr4+ atoms to form a mixture of distorted edge and corner-sharing OSm2Zr2 tetrahedra. In the twentieth O2- site, O2- is bonded to four Sm3+ atoms to form a mixture of edge and corner-sharing OSm4 tetrahedra.