DOI: 10.17188/1722167
title: Materials Data on K38Nb7As24 by Materials Project

description: K38Nb7As24 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are twenty-six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to five As3- atoms to form distorted KAs5 square pyramids that share a cornercorner with one NbAs4 tetrahedra and edges with two NbAs4 tetrahedra. There are a spread of K–As bond distances ranging from 3.48–3.57 Å. In the second K1+ site, K1+ is bonded to five As3- atoms to form distorted KAs5 square pyramids that share a cornercorner with one NbAs4 tetrahedra, corners with two equivalent KAs4 trigonal pyramids, and edges with two NbAs4 tetrahedra. There are a spread of K–As bond distances ranging from 3.48–3.59 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six As3- atoms. There are a spread of K–As bond distances ranging from 3.45–3.77 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five As3- atoms. There are a spread of K–As bond distances ranging from 3.46–3.60 Å. In the fifth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.33–3.67 Å. In the sixth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.32–3.67 Å. In the seventh K1+ site, K1+ is bonded in a 5-coordinate geometry to five As3- atoms. There are a spread of K–As bond distances ranging from 3.22–3.74 Å. In the eighth K1+ site, K1+ is bonded in a 5-coordinate geometry to five As3- atoms. There are a spread of K–As bond distances ranging from 3.22–3.62 Å. In the ninth K1+ site, K1+ is bonded in a 6-coordinate geometry to six As3- atoms. There are a spread of K–As bond distances ranging from 3.27–3.60 Å. In the tenth K1+ site, K1+ is bonded in a 2-coordinate geometry to four As3- atoms. There are two shorter (3.43 Å) and two longer (3.83 Å) K–As bond lengths. In the eleventh K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are two shorter (3.39 Å) and two longer (3.82 Å) K–As bond lengths. In the twelfth K1+ site, K1+ is bonded in a 6-coordinate geometry to six As3- atoms. There are a spread of K–As bond distances ranging from 3.32–3.66 Å. In the thirteenth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.29–3.58 Å. In the fourteenth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.37–3.70 Å. In the fifteenth K1+ site, K1+ is bonded in a 4-coordinate geometry to six As3- atoms. There are a spread of K–As bond distances ranging from 3.41–3.75 Å. In the sixteenth K1+ site, K1+ is bonded in a 3-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.49–3.77 Å. In the seventeenth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.43–3.76 Å. In the eighteenth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.22–3.55 Å. In the nineteenth K1+ site, K1+ is bonded to four As3- atoms to form distorted KAs4 trigonal pyramids that share corners with two equivalent KAs5 square pyramids, corners with two equivalent NbAs4 tetrahedra, and an edgeedge with one NbAs4 tetrahedra. There are a spread of K–As bond distances ranging from 3.36–3.48 Å. In the twentieth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.20–3.44 Å. In the twenty-first K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.29–3.47 Å. In the twenty-second K1+ site, K1+ is bonded in a 5-coordinate geometry to five As3- atoms. There are a spread of K–As bond distances ranging from 3.35–3.74 Å. In the twenty-third K1+ site, K1+ is bonded in a 5-coordinate geometry to five As3- atoms. There are a spread of K–As bond distances ranging from 3.38–3.78 Å. In the twenty-fourth K1+ site, K1+ is bonded in a distorted bent 150 degrees geometry to three As3- atoms. There are two shorter (3.28 Å) and one longer (3.88 Å) K–As bond lengths. In the twenty-fifth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As3- atoms. There are a spread of K–As bond distances ranging from 3.42–3.47 Å. In the twenty-sixth K1+ site, K1+ is bonded in a 3-coordinate geometry to three As3- atoms. There are one shorter (3.67 Å) and two longer (3.78 Å) K–As bond lengths. There are seven inequivalent Nb+4.86+ sites. In the first Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form NbAs4 tetrahedra that share corners with two KAs5 square pyramids. There are two shorter (2.52 Å) and two longer (2.57 Å) Nb–As bond lengths. In the second Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form NbAs4 tetrahedra that share an edgeedge with one KAs5 square pyramid. There are one shorter (2.48 Å) and three longer (2.56 Å) Nb–As bond lengths. In the third Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form NbAs4 tetrahedra that share an edgeedge with one KAs5 square pyramid and an edgeedge with one KAs4 trigonal pyramid. There are a spread of Nb–As bond distances ranging from 2.52–2.55 Å. In the fourth Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form edge-sharing NbAs4 tetrahedra. There are a spread of Nb–As bond distances ranging from 2.47–2.59 Å. In the fifth Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form edge-sharing NbAs4 tetrahedra. There are a spread of Nb–As bond distances ranging from 2.47–2.59 Å. In the sixth Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form NbAs4 tetrahedra that share an edgeedge with one KAs5 square pyramid and an edgeedge with one NbAs4 tetrahedra. There are a spread of Nb–As bond distances ranging from 2.52–2.57 Å. In the seventh Nb+4.86+ site, Nb+4.86+ is bonded to four As3- atoms to form NbAs4 tetrahedra that share corners with two equivalent KAs4 trigonal pyramids, an edgeedge with one KAs5 square pyramid, and an edgeedge with one NbAs4 tetrahedra. There are two shorter (2.48 Å) and two longer (2.58 Å) Nb–As bond lengths. There are eighteen inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the second As3- site, As3- is bonded in a 1-coordinate geometry to eight K1+ and one Nb+4.86+ atom. In the third As3- site, As3- is bonded in a 1-coordinate geometry to eight K1+ and one Nb+4.86+ atom. In the fourth As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the fifth As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the sixth As3- site, As3- is bonded in a 1-coordinate geometry to eight K1+ and one Nb+4.86+ atom. In the seventh As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the eighth As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the ninth As3- site, As3- is bonded in a 1-coordinate geometry to eight K1+ and one Nb+4.86+ atom. In the tenth As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the eleventh As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the twelfth As3- site, As3- is bonded in a 2-coordinate geometry to six K1+ and two Nb+4.86+ atoms. In the thirteenth As3- site, As3- is bonded in a 2-coordinate geometry to six K1+ and two Nb+4.86+ atoms. In the fourteenth As3- site, As3- is bonded in a 1-coordinate geometry to seven K1+ and one Nb+4.86+ atom. In the fifteenth As3- site, As3- is bonded in a 1-coordinate geometry to six K1+ and one Nb+4.86+ atom. In the sixteenth As3- site, As3- is bonded in a 1-coordinate geometry to nine K1+ and one Nb+4.86+ atom. In the seventeenth As3- site, As3- is bonded in a 1-coordinate geometry to nine K1+ and one Nb+4.86+ atom. In the eighteenth As3- site, As3- is bonded in a 9-coordinate geometry to seven K1+ and two Nb+4.86+ atoms.