Materials Data on NaAsSe2 by Materials Project

Abstract

NaAsSe2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 14–21°. There are a spread of Na–Se bond distances ranging from 2.98–3.18 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 15–21°. There are a spread of Na–Se bond distances ranging from 2.98–3.20 Å. There are two inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.35–2.51 Å. In the second As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.35–2.51 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a see-saw-like geometry to two Na1+ and two equivalent As3+ atoms. In the second Se2- site, Se2- is bonded to four equivalent Na1+ and one As3+ atom to form a mixture of edge and corner-sharing SeNa4As square pyramids. In the third Se2- site, Se2- is bonded to four equivalent Na1+ and one As3+ atom to form a mixture of edge and corner-sharing SeNa4As square pyramids. In the fourth Se2- site, Se2- is bonded in a see-saw-like geometry to two Na1+ and two equivalent As3+ atoms.