Materials Data on Sr2Gd2TlNi2O9 by Materials Project

Abstract

Tl(Gd2Sr2)Ni2O9 is (La,Ba)CuO4-derived structured and crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–2.77 Å. Gd3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Gd–O bond distances ranging from 2.24–2.76 Å. Ni+3.50+ is bonded to six O2- atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Ni–O bond distances ranging from 1.91–2.28 Å. Tl1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Tl–O bond distances ranging from 2.12–3.05 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to five equivalent Gd3+ and one Ni+3.50+ atom. In the second O2- site, O2- is bonded to two equivalent Sr2+ and four equivalent Tl1+ atoms to form a mixture of distorted edge and corner-sharing OSr2Tl4 octahedra. The corner-sharing octahedra tilt angles range from 0–47°. In the third O2- site, O2- is bonded to four equivalent Sr2+, one Ni+3.50+, and one Tl1+ atom to form distorted OSr4TlNi octahedra that share corners with thirteen OSr4TlNi octahedra, edges with eight OSr2Tl4 octahedra, and faces with four equivalent OSr2Gd2Ni2 octahedra. The corner-sharing octahedra tilt angles range from 13–54°. In the fourth O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Gd3+, and two equivalent Ni+3.50+ atoms to form distorted OSr2Gd2Ni2 octahedra that share corners with eight OSr2Tl4 octahedra, edges with two equivalent OSr2Gd2Ni2 octahedra, and faces with six OSr4TlNi octahedra. The corner-sharing octahedra tilt angles range from 5–54°.