DOE OSTI2020
MnO2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Mn4+ sites. In the first Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one MnO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.86–2.02 Å. In the second Mn4+ site, Mn4+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.95 Å. In the third Mn4+ site, Mn4+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.91–1.96 Å. In the fourth Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one MnO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.84–2.01 Å. In the fifth Mn4+ site, Mn4+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.95 Å. In the sixth Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one MnO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.87–2.02 Å. In the seventh Mn4+ site, Mn4+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–1.95 Å. In the eighth Mn4+ site, Mn4+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.95 Å. In the ninth Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–1.95 Å. In the tenth Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO4 tetrahedra and edges with five MnO6 octahedra. There is three shorter (1.93 Å) and three longer (1.94 Å) Mn–O bond length. In the eleventh Mn4+ site, Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO4 tetrahedra and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–1.95 Å. In the twelfth Mn4+ site, Mn4+ is bonded to four O2- atoms to form corner-sharing MnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–59°. There are a spread of Mn–O bond distances ranging from 1.91–2.00 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two Mn4+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to two Mn4+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to two Mn4+ atoms. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Mn4+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn4+ atoms. In the tenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn4+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn4+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn4+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn4+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn4+ atoms. In the twentieth O2- site, O2- is bonded in a distorted T-shaped geometry to three Mn4+ atoms. In the twenty-first O2- site, O2- is bonded in a trigonal planar geometry to three Mn4+ atoms. In the twenty-second O2- site, O2- is bonded in a trigonal planar geometry to three Mn4+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a trigonal planar geometry to three Mn4+ atoms.