Materials Data on BaNaPO4 by Materials Project

Abstract

NaBaPO4 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six PO4 tetrahedra, edges with three equivalent NaO7 hexagonal pyramids, and faces with two equivalent BaO12 cuboctahedra. There are three shorter (2.32 Å) and three longer (2.41 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 hexagonal pyramids that share corners with six equivalent NaO7 hexagonal pyramids, a cornercorner with one PO4 tetrahedra, edges with three equivalent NaO6 octahedra, edges with three equivalent PO4 tetrahedra, and faces with three equivalent BaO12 cuboctahedra. There are one shorter (2.31 Å) and six longer (2.86 Å) Na–O bond lengths. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent BaO12 cuboctahedra, edges with six PO4 tetrahedra, faces with three equivalent NaO7 hexagonal pyramids, and faces with two equivalent NaO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.79–3.29 Å. In the second Ba2+ site, Ba2+ is bonded in a 1-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.61–2.97 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one NaO7 hexagonal pyramid, corners with three equivalent NaO6 octahedra, and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 20°. There is one shorter (1.54 Å) and three longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NaO6 octahedra, edges with three equivalent BaO12 cuboctahedra, and edges with three equivalent NaO7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 16°. There is one shorter (1.54 Å) and three longer (1.56 Å) P–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, three Ba2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, two Ba2+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to one Na1+, three equivalent Ba2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four Ba2+ and one P5+ atom.