Materials Data on BaMnO2 by Materials Project
BaMnO2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.68–3.16 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ba–O bond distances ranging from 2.62–3.07 Å. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.82–3.37 Å. There are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four O2- atoms to form a mixture of edge and corner-sharing MnO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.03–2.14 Å. In the second Mn2+ site, Mn2+ is bonded to four O2- atoms to form corner-sharing MnO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.03–2.11 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and two equivalent Mn2+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ba2+ and two Mn2+ atoms. In the third O2- site, O2- is bonded to four Ba2+ and two equivalent Mn2+ atoms to form a mixture of distorted edge and corner-sharing OBa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 61–73°. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and two equivalent Mn2+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Ba2+ and two Mn2+ atoms. In the sixth O2- site, O2- is bonded to four Ba2+ and two equivalent Mn2+ atoms to form a mixture of distorted edge and corner-sharing OBa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 50–61°.