DOI: 10.17188/1683699
title: Materials Data on Na20Zn7Sn12 by Materials Project

description: Na20Zn7Sn12 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are ten inequivalent Na sites. In the first Na site, Na is bonded to four Sn atoms to form distorted NaSn4 tetrahedra that share corners with two equivalent ZnNa4Sn2 octahedra, corners with three equivalent NaNaSn4 tetrahedra, and edges with two NaSn4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–84°. There are a spread of Na–Sn bond distances ranging from 3.34–3.57 Å. In the second Na site, Na is bonded in a 4-coordinate geometry to six Na, four Zn, and five Sn atoms. There are a spread of Na–Na bond distances ranging from 3.54–3.91 Å. There are a spread of Na–Zn bond distances ranging from 3.25–3.41 Å. There are a spread of Na–Sn bond distances ranging from 3.22–3.66 Å. In the third Na site, Na is bonded to one Na and four Sn atoms to form distorted NaNaSn4 tetrahedra that share corners with two equivalent ZnNa4Sn2 octahedra, corners with three equivalent NaSn4 tetrahedra, and edges with two NaSn4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–85°. There are a spread of Na–Sn bond distances ranging from 3.33–3.53 Å. In the fourth Na site, Na is bonded in a 5-coordinate geometry to one Na, two Zn, and four Sn atoms. There are one shorter (3.34 Å) and one longer (3.56 Å) Na–Zn bond lengths. There are a spread of Na–Sn bond distances ranging from 3.30–3.43 Å. In the fifth Na site, Na is bonded in a 5-coordinate geometry to one Na, two Zn, and four Sn atoms. There are one shorter (3.28 Å) and one longer (3.47 Å) Na–Zn bond lengths. There are a spread of Na–Sn bond distances ranging from 3.37–3.44 Å. In the sixth Na site, Na is bonded in a distorted trigonal planar geometry to one Zn and two equivalent Sn atoms. The Na–Zn bond length is 2.98 Å. There are one shorter (3.18 Å) and one longer (3.19 Å) Na–Sn bond lengths. In the seventh Na site, Na is bonded in a 2-coordinate geometry to one Na, three Zn, and six Sn atoms. There are a spread of Na–Zn bond distances ranging from 3.33–3.36 Å. There are a spread of Na–Sn bond distances ranging from 3.21–3.68 Å. In the eighth Na site, Na is bonded in a 8-coordinate geometry to two equivalent Na, three Zn, and five Sn atoms. There are a spread of Na–Zn bond distances ranging from 3.25–3.40 Å. There are a spread of Na–Sn bond distances ranging from 3.23–3.52 Å. In the ninth Na site, Na is bonded in a 5-coordinate geometry to one Zn and four Sn atoms. The Na–Zn bond length is 3.28 Å. There are a spread of Na–Sn bond distances ranging from 3.29–3.45 Å. In the tenth Na site, Na is bonded in a 4-coordinate geometry to one Zn and five Sn atoms. The Na–Zn bond length is 3.48 Å. There are a spread of Na–Sn bond distances ranging from 3.39–3.59 Å. There are four inequivalent Zn sites. In the first Zn site, Zn is bonded in a 11-coordinate geometry to five Na, one Zn, and five Sn atoms. The Zn–Zn bond length is 2.84 Å. There are a spread of Zn–Sn bond distances ranging from 2.67–3.12 Å. In the second Zn site, Zn is bonded in a 11-coordinate geometry to five Na, two Zn, and four Sn atoms. The Zn–Zn bond length is 2.79 Å. There are a spread of Zn–Sn bond distances ranging from 2.81–3.01 Å. In the third Zn site, Zn is bonded in a 11-coordinate geometry to five Na, two Zn, and four Sn atoms. The Zn–Zn bond length is 2.75 Å. There are a spread of Zn–Sn bond distances ranging from 2.85–2.92 Å. In the fourth Zn site, Zn is bonded to four Na and two equivalent Sn atoms to form distorted ZnNa4Sn2 octahedra that share corners with eight NaSn4 tetrahedra. Both Zn–Sn bond lengths are 2.60 Å. There are six inequivalent Sn sites. In the first Sn site, Sn is bonded in a 11-coordinate geometry to five Na, three Zn, and three Sn atoms. There are a spread of Sn–Sn bond distances ranging from 2.97–3.03 Å. In the second Sn site, Sn is bonded in a 11-coordinate geometry to six Na, three Zn, and two Sn atoms. The Sn–Sn bond length is 3.00 Å. In the third Sn site, Sn is bonded in a 9-coordinate geometry to eight Na and one Zn atom. In the fourth Sn site, Sn is bonded in a 11-coordinate geometry to six Na, four Zn, and one Sn atom. In the fifth Sn site, Sn is bonded in a 12-coordinate geometry to nine Na, two Zn, and one Sn atom. In the sixth Sn site, Sn is bonded in a 10-coordinate geometry to nine Na and one Zn atom.