Materials Data on NaMoAsO6 by Materials Project

Abstract

NaMoO2AsO4 crystallizes in the orthorhombic Pca2_1 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 distorted NaO6 pentagonal pyramids that share corners with three MoO6 octahedra, corners with three AsO4 tetrahedra, and a faceface with one MoO6 octahedra. The corner-sharing octahedra tilt angles range from 33–52°. There are a spread of Na–O bond distances ranging from 2.40–2.60 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.60 Å. There are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share corners with two equivalent NaO6 pentagonal pyramids and corners with four AsO4 tetrahedra. There are a spread of Mo–O bond distances ranging from 1.74–2.25 Å. In the second Mo6+ site, Mo6+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share a cornercorner with one NaO6 pentagonal pyramid, corners with four AsO4 tetrahedra, and a faceface with one NaO6 pentagonal pyramid. There are a spread of Mo–O bond distances ranging from 1.74–2.24 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four MoO6 octahedra and corners with two equivalent NaO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 46–57°. There are a spread of As–O bond distances ranging from 1.70–1.74 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four MoO6 octahedra and a cornercorner with one NaO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 47–56°. There are a spread of As–O bond distances ranging from 1.70–1.74 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one Mo6+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one Mo6+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom.