Materials Data on Ca3(InAs2)2 by Materials Project

Abstract

Ca3(InAs2)2 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six As3- atoms to form CaAs6 octahedra that share corners with seven CaAs6 octahedra, corners with six equivalent InAs4 tetrahedra, edges with six equivalent CaAs6 octahedra, edges with three equivalent InAs4 tetrahedra, and a faceface with one CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 13–55°. There are a spread of Ca–As bond distances ranging from 3.07–3.49 Å. In the second Ca2+ site, Ca2+ is bonded to six As3- atoms to form CaAs6 octahedra that share corners with ten equivalent CaAs6 octahedra, corners with four equivalent InAs4 tetrahedra, edges with two equivalent CaAs6 octahedra, edges with four equivalent InAs4 tetrahedra, and faces with two equivalent CaAs6 octahedra. The corner-sharing octahedra tilt angles range from 32–55°. There are four shorter (3.02 Å) and two longer (3.30 Å) Ca–As bond lengths. In3+ is bonded to four As3- atoms to form InAs4 tetrahedra that share corners with eight CaAs6 octahedra, corners with two equivalent InAs4 tetrahedra, edges with five CaAs6 octahedra, and an edgeedge with one InAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 22–68°. There are a spread of In–As bond distances ranging from 2.76–2.80 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to four Ca2+ and two equivalent In3+ atoms to form distorted AsCa4In2 pentagonal pyramids that share corners with two equivalent AsCa5In2 pentagonal bipyramids, corners with two equivalent AsCa4In2 pentagonal pyramids, edges with seven equivalent AsCa5In2 pentagonal bipyramids, and edges with four equivalent AsCa4In2 pentagonal pyramids. In the second As3- site, As3- is bonded to five Ca2+ and two equivalent In3+ atoms to form distorted AsCa5In2 pentagonal bipyramids that share corners with three equivalent AsCa5In2 pentagonal bipyramids, corners with two equivalent AsCa4In2 pentagonal pyramids, edges with six equivalent AsCa5In2 pentagonal bipyramids, and edges with seven equivalent AsCa4In2 pentagonal pyramids.