Materials Data on Na3Pr(AsO4)2 by Materials Project

Abstract

Na3Pr(AsO4)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted single-bond geometry to seven O2- atoms. There are one shorter (2.14 Å) and six longer (2.98 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Na–O bond lengths are 2.93 Å. Pr3+ is bonded to six equivalent O2- atoms to form PrO6 octahedra that share corners with six equivalent AsO4 tetrahedra. All Pr–O bond lengths are 2.34 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent PrO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There is one shorter (1.67 Å) and three longer (1.73 Å) As–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to one Na1+ and one As5+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Pr3+, and one As5+ atom.