Materials Data on Sr2Mn2O5 by Materials Project
Sr2Mn2O5 crystallizes in the orthorhombic Ima2 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 2.50–3.09 Å. There are two inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent MnO6 octahedra and corners with two equivalent MnO4 tetrahedra. The corner-sharing octahedral tilt angles are 5°. There are four shorter (1.98 Å) and two longer (2.26 Å) Mn–O bond lengths. In the second Mn3+ site, Mn3+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with two equivalent MnO6 octahedra and corners with two equivalent MnO4 tetrahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Mn–O bond distances ranging from 1.89–2.01 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Mn3+ atoms to form distorted OSr4Mn2 octahedra that share corners with two equivalent OSr4Mn2 octahedra, corners with four equivalent OSr2Mn2 tetrahedra, edges with two equivalent OSr4Mn2 octahedra, and faces with four equivalent OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Sr2+ and two Mn3+ atoms. In the third O2- site, O2- is bonded to two equivalent Sr2+ and two equivalent Mn3+ atoms to form distorted OSr2Mn2 tetrahedra that share corners with eight equivalent OSr4Mn2 octahedra and corners with two equivalent OSr2Mn2 tetrahedra. The corner-sharing octahedra tilt angles range from 23–74°.