DOE OSTI2020
Nd2Mn3Sb3O14 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Nd3+ is bonded to eight O2- atoms to form NdO8 hexagonal bipyramids that share edges with two equivalent NdO8 hexagonal bipyramids, edges with four MnO8 hexagonal bipyramids, edges with two equivalent MnO6 octahedra, and edges with four SbO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.37–2.58 Å. There are three inequivalent Mn+2.33+ sites. In the first Mn+2.33+ site, Mn+2.33+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six SbO6 octahedra, edges with two equivalent MnO8 hexagonal bipyramids, and edges with four equivalent NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 48–53°. There are four shorter (1.99 Å) and two longer (2.16 Å) Mn–O bond lengths. In the second Mn+2.33+ site, Mn+2.33+ is bonded to eight O2- atoms to form distorted MnO8 hexagonal bipyramids that share edges with two equivalent MnO8 hexagonal bipyramids, edges with four equivalent NdO8 hexagonal bipyramids, and edges with six SbO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.11–2.64 Å. In the third Mn+2.33+ site, Mn+2.33+ is bonded to eight O2- atoms to form distorted MnO8 hexagonal bipyramids that share edges with two equivalent MnO8 hexagonal bipyramids, edges with four equivalent NdO8 hexagonal bipyramids, edges with two equivalent MnO6 octahedra, and edges with four equivalent SbO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.20–2.61 Å. There are two inequivalent Sb5+ sites. In the first Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with four equivalent SbO6 octahedra, edges with two equivalent MnO8 hexagonal bipyramids, and edges with four equivalent NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–53°. There is two shorter (1.96 Å) and four longer (2.02 Å) Sb–O bond length. In the second Sb5+ site, Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with four SbO6 octahedra, edges with two equivalent NdO8 hexagonal bipyramids, and edges with four MnO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–48°. There are a spread of Sb–O bond distances ranging from 1.99–2.02 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Nd3+ and two Mn+2.33+ atoms to form ONd2Mn2 tetrahedra that share corners with six ONd2Mn2 tetrahedra and an edgeedge with one ONd2MnSb tetrahedra. In the second O2- site, O2- is bonded to two equivalent Nd3+, one Mn+2.33+, and one Sb5+ atom to form a mixture of distorted edge and corner-sharing ONd2MnSb tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Mn+2.33+ and two equivalent Sb5+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Nd3+, two Mn+2.33+, and one Sb5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Nd3+, one Mn+2.33+, and two Sb5+ atoms.