DOI: 10.17188/1715498
title: Materials Data on Na2MoAs2O9 by Materials Project

description: Na2MoAs2O9 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.41–3.10 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.41–3.09 Å. In the third Na1+ site, Na1+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.53 Å. In the fourth Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with two MoO6 octahedra and corners with three AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 15–19°. There are a spread of Na–O bond distances ranging from 2.25–2.77 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 four AsO4 tetrahedra and a cornercorner with one NaO5 trigonal bipyramid. There are a spread of Mo–O bond distances ranging from 1.73–2.27 Å. In the second Mo6+ site, Mo6+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share corners with four AsO4 tetrahedra and a cornercorner with one NaO5 trigonal bipyramid. There are a spread of Mo–O bond distances ranging from 1.73–2.26 Å. There are four inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two MoO6 octahedra, a cornercorner with one AsO4 tetrahedra, and a cornercorner with one NaO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of As–O bond distances ranging from 1.68–1.80 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two MoO6 octahedra and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are a spread of As–O bond distances ranging from 1.68–1.80 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two MoO6 octahedra, a cornercorner with one AsO4 tetrahedra, and a cornercorner with one NaO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of As–O bond distances ranging from 1.66–1.81 Å. In the fourth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two MoO6 octahedra, a cornercorner with one AsO4 tetrahedra, and a cornercorner with one NaO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of As–O bond distances ranging from 1.66–1.81 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Mo6+, and one As5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Mo6+, and one As5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Mo6+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Mo6+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Mo6+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one Na1+ and one Mo6+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Na1+ and one As5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the thirteenth O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one As5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Na1+ and one As5+ atom. In the fifteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Na1+ and two As5+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Na1+ and two As5+ atoms. In the seventeenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one As5+ atom. In the eighteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one As5+ atom.