DOE OSTI2020
Na2TbO3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seventeen inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–3.06 Å. In the second Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.23–2.47 Å. In the third Na1+ site, Na1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.98 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.32–2.59 Å. In the fifth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.65 Å. In the sixth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.87 Å. In the seventh Na1+ site, Na1+ is bonded to six O2- atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.38–2.47 Å. In the eighth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.93 Å. In the ninth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.26–2.72 Å. In the tenth Na1+ site, Na1+ is bonded in a 4-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.93 Å. In the eleventh Na1+ site, Na1+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.57 Å. In the twelfth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.31–2.52 Å. In the thirteenth Na1+ site, Na1+ is bonded in a 3-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.24–2.89 Å. In the fourteenth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.76 Å. In the fifteenth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.24–2.82 Å. In the sixteenth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.21–2.67 Å. In the seventeenth Na1+ site, Na1+ is bonded to six O2- atoms to form distorted edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.31–2.58 Å. There are eight inequivalent Tb4+ sites. In the first Tb4+ site, Tb4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Tb–O bond distances ranging from 2.23–2.45 Å. In the second Tb4+ site, Tb4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.21–2.81 Å. In the third Tb4+ site, Tb4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Tb–O bond distances ranging from 2.29–2.79 Å. In the fourth Tb4+ site, Tb4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.28–2.57 Å. In the fifth Tb4+ site, Tb4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.32–2.52 Å. In the sixth Tb4+ site, Tb4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.23–2.72 Å. In the seventh Tb4+ site, Tb4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.22–2.46 Å. In the eighth Tb4+ site, Tb4+ is bonded in a 6-coordinate geometry to seven O2- atoms. There are a spread of Tb–O bond distances ranging from 2.28–2.62 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to six Na1+ and one Tb4+ atom to form distorted ONa6Tb pentagonal bipyramids that share corners with two ONa3Tb3 octahedra, a cornercorner with one ONa6Tb pentagonal bipyramid, and edges with three ONa3Tb3 octahedra. The corner-sharing octahedra tilt angles range from 40–58°. In the second O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Tb4+ atom. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Tb4+ atom. In the fourth O2- site, O2- is bonded in a 7-coordinate geometry to four Na1+ and three Tb4+ atoms. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Tb4+ atom. In the sixth O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Tb4+ atom. In the seventh O2- site, O2- is bonded in a 8-coordinate geometry to five Na1+, two Tb4+, and one O2- atom. The O–O bond length is 1.54 Å. In the eighth O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form distorted ONa3Tb3 octahedra that share edges with three ONa3Tb3 octahedra and an edgeedge with one ONa6Tb pentagonal bipyramid. In the ninth O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form distorted ONa3Tb3 octahedra that share a cornercorner with one ONa3Tb3 octahedra, a cornercorner with one ONa6Tb pentagonal bipyramid, edges with two ONa3Tb3 octahedra, and edges with two equivalent ONa6Tb pentagonal bipyramids. The corner-sharing octahedral tilt angles are 0°. In the tenth O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and three Tb4+ atoms. In the eleventh O2- site, O2- is bonded in a 7-coordinate geometry to three Na1+, three Tb4+, and one O2- atom. The O–O bond length is 1.53 Å. In the twelfth O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form distorted ONa3Tb3 octahedra that share a cornercorner with one ONa6Tb pentagonal bipyramid, edges with three ONa3Tb3 octahedra, and an edgeedge with one ONa6Tb pentagonal bipyramid. In the thirteenth O2- site, O2- is bonded in a 6-coordinate geometry to three Na1+, two Tb4+, and one O2- atom. In the fourteenth O2- site, O2- is bonded to six Na1+ and one Tb4+ atom to form distorted ONa6Tb pentagonal bipyramids that share corners with two ONa3Tb3 octahedra, corners with two ONa6Tb pentagonal bipyramids, and edges with three ONa3Tb3 octahedra. The corner-sharing octahedra tilt angles range from 13–49°. In the fifteenth O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and three Tb4+ atoms. In the sixteenth O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form distorted ONa3Tb3 octahedra that share a cornercorner with one ONa3Tb3 octahedra, a cornercorner with one ONa6Tb pentagonal bipyramid, edges with two ONa3Tb3 octahedra, and an edgeedge with one ONa6Tb pentagonal bipyramid. The corner-sharing octahedral tilt angles are 15°. In the seventeenth O2- site, O2- is bonded in a 7-coordinate geometry to four Na1+ and three Tb4+ atoms. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to four Na1+, three Tb4+, and one O2- atom. In the nineteenth O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form distorted ONa3Tb3 octahedra that share a cornercorner with one ONa3Tb3 octahedra, a cornercorner with one ONa6Tb pentagonal bipyramid, edges with three ONa3Tb3 octahedra, and an edgeedge with one ONa6Tb pentagonal bipyramid. The corner-sharing octahedral tilt angles are 15°. In the twentieth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and three Tb4+ atoms. In the twenty-first O2- site, O2- is bonded to three Na1+ and three Tb4+ atoms to form a mixture of edge and corner-sharing ONa3Tb3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the twenty-second O2- site, O2- is bonded in a 6-coordinate geometry to three Na1+ and three Tb4+ atoms. In the twenty-third O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+ and three Tb4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Tb4+ atom.