Materials Data on NaCa2Mg2V3O12 by Materials Project

Abstract

Ca2NaMg2V3O12 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.50 Å) and four longer (2.60 Å) Na–O bond lengths. Ca2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–2.57 Å. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six VO4 tetrahedra. There are four shorter (2.10 Å) and two longer (2.11 Å) Mg–O bond lengths. There are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to four equivalent O2- atoms to form VO4 tetrahedra that share corners with four equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 49°. All V–O bond lengths are 1.75 Å. In the second V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with four equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 47–50°. There is two shorter (1.73 Å) and two longer (1.76 Å) V–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Mg2+, and one V5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ca2+, one Mg2+, and one V5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+, one Mg2+, and one V5+ atom.