DOI: 10.17188/1202933
title: Materials Data on Na4Cd3Se5 by Materials Project

description: Na4Cd3Se5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to five Se2- atoms to form distorted NaSe5 trigonal bipyramids that share corners with two equivalent NaSe6 octahedra, corners with three equivalent NaSe5 square pyramids, corners with six CdSe4 tetrahedra, corners with four equivalent NaSe5 trigonal bipyramids, edges with two equivalent CdSe4 tetrahedra, edges with four NaSe5 trigonal bipyramids, and a faceface with one NaSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are a spread of Na–Se bond distances ranging from 2.97–3.17 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with three equivalent NaSe5 square pyramids, corners with five CdSe4 tetrahedra, corners with four NaSe5 trigonal bipyramids, edges with four equivalent NaSe6 octahedra, edges with five CdSe4 tetrahedra, an edgeedge with one NaSe5 trigonal bipyramid, and a faceface with one NaSe5 trigonal bipyramid. There are a spread of Na–Se bond distances ranging from 3.04–3.49 Å. In the third Na1+ site, Na1+ is bonded to five Se2- atoms to form NaSe5 square pyramids that share corners with three equivalent NaSe6 octahedra, corners with four CdSe4 tetrahedra, corners with five NaSe5 trigonal bipyramids, edges with four equivalent NaSe5 square pyramids, and edges with four CdSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–53°. There are a spread of Na–Se bond distances ranging from 3.11–3.19 Å. In the fourth Na1+ site, Na1+ is bonded to five Se2- atoms to form distorted NaSe5 trigonal bipyramids that share corners with two equivalent NaSe6 octahedra, corners with two equivalent NaSe5 square pyramids, corners with three CdSe4 tetrahedra, corners with four equivalent NaSe5 trigonal bipyramids, an edgeedge with one NaSe6 octahedra, edges with four CdSe4 tetrahedra, and edges with four NaSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 33°. There are a spread of Na–Se bond distances ranging from 2.88–3.12 Å. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent NaSe6 octahedra, corners with six CdSe4 tetrahedra, corners with four equivalent NaSe5 trigonal bipyramids, edges with three equivalent NaSe6 octahedra, and edges with two equivalent NaSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. There are a spread of Cd–Se bond distances ranging from 2.67–2.77 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with two equivalent NaSe6 octahedra, corners with two equivalent NaSe5 square pyramids, corners with six CdSe4 tetrahedra, corners with two equivalent NaSe5 trigonal bipyramids, an edgeedge with one NaSe5 square pyramid, and edges with four NaSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 48°. There are a spread of Cd–Se bond distances ranging from 2.65–2.77 Å. In the third Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share a cornercorner with one NaSe6 octahedra, corners with two equivalent NaSe5 square pyramids, corners with six CdSe4 tetrahedra, corners with three NaSe5 trigonal bipyramids, edges with two equivalent NaSe6 octahedra, and edges with three equivalent NaSe5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Cd–Se bond distances ranging from 2.69–2.71 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 7-coordinate geometry to five Na1+ and two equivalent Cd2+ atoms. In the second Se2- site, Se2- is bonded in a 8-coordinate geometry to six Na1+ and two Cd2+ atoms. In the third Se2- site, Se2- is bonded to three equivalent Na1+ and three Cd2+ atoms to form SeNa3Cd3 octahedra that share a cornercorner with one SeNa3Cd3 octahedra, corners with two equivalent SeNa4Cd2 pentagonal pyramids, and edges with four equivalent SeNa3Cd3 octahedra. The corner-sharing octahedral tilt angles are 70°. In the fourth Se2- site, Se2- is bonded to three Na1+ and three Cd2+ atoms to form SeNa3Cd3 octahedra that share a cornercorner with one SeNa3Cd3 octahedra, corners with four equivalent SeNa4Cd2 pentagonal pyramids, and edges with two equivalent SeNa3Cd3 octahedra. The corner-sharing octahedral tilt angles are 70°. In the fifth Se2- site, Se2- is bonded to four Na1+ and two Cd2+ atoms to form distorted SeNa4Cd2 pentagonal pyramids that share corners with six SeNa3Cd3 octahedra and edges with two equivalent SeNa4Cd2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 61–74°.