Materials Data on Zr21S8 by Materials Project
Zr21S8 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are six inequivalent Zr sites. In the first Zr site, Zr is bonded in a square co-planar geometry to four equivalent S atoms. All Zr–S bond lengths are 2.84 Å. In the second Zr site, Zr is bonded in a single-bond geometry to one S atom. The Zr–S bond length is 2.83 Å. In the third Zr site, Zr is bonded in a 3-coordinate geometry to three S atoms. There are one shorter (2.63 Å) and two longer (2.68 Å) Zr–S bond lengths. In the fourth Zr site, Zr is bonded in a 2-coordinate geometry to two equivalent S atoms. Both Zr–S bond lengths are 2.61 Å. In the fifth Zr site, Zr is bonded in a 3-coordinate geometry to four S atoms. There are a spread of Zr–S bond distances ranging from 2.66–3.20 Å. In the sixth Zr site, Zr is bonded in a 4-coordinate geometry to four equivalent S atoms. There are two shorter (2.65 Å) and two longer (2.66 Å) Zr–S bond lengths. There are two inequivalent S sites. In the first S site, S is bonded in a 7-coordinate geometry to seven Zr atoms. In the second S site, S is bonded in a 7-coordinate geometry to eight Zr atoms.