Materials Data on Ta2Mn3O8 by Materials Project
Ta2Mn3O8 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with two equivalent MnO4 tetrahedra, and an edgeedge with one TaO6 octahedra. The corner-sharing octahedral tilt angles are 29°. There are a spread of Ta–O bond distances ranging from 1.94–2.15 Å. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four equivalent O2- atoms to form MnO4 tetrahedra that share corners with eight equivalent TaO6 octahedra. The corner-sharing octahedral tilt angles are 62°. All Mn–O bond lengths are 2.03 Å. In the second Mn2+ site, Mn2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.23 Å) and four longer (2.68 Å) Mn–O bond lengths. In the third Mn2+ site, Mn2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Mn–O bond distances ranging from 2.03–2.85 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Ta5+ and two equivalent Mn2+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ta5+ and three Mn2+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ta5+ and two Mn2+ atoms. In the fourth O2- site, O2- is bonded to one Ta5+ and three Mn2+ atoms to form a mixture of distorted edge and corner-sharing OTaMn3 tetrahedra.