Materials Data on Sr2Nb2O7 by Materials Project

Abstract

Sr2Nb2O7 is Pb (Zr_0.50 Ti_0.48) O_3-like structured and crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.76 Å. In the second Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–3.06 Å. In the third Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.53–2.92 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sr–O bond distances ranging from 2.51–2.60 Å. There are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 16–38°. There are a spread of Nb–O bond distances ranging from 1.83–2.40 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 12–38°. There are a spread of Nb–O bond distances ranging from 1.86–2.35 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 12–36°. There are a spread of Nb–O bond distances ranging from 1.86–2.35 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 16–36°. There are a spread of Nb–O bond distances ranging from 1.86–2.38 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form distorted corner-sharing OSr3Nb tetrahedra. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two Sr2+ and one Nb5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Sr2+ and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+ and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the tenth O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form distorted corner-sharing OSr3Nb tetrahedra. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two Nb5+ atoms. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+ and two Nb5+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Nb5+ atoms.