DOI: 10.17188/1738653
title: Materials Data on Ta4Se8SI8 by Materials Project

description: Ta4Se8SI8 crystallizes in the orthorhombic Pna2_1 space group. The structure is zero-dimensional and consists of four Ta4Se8SI8 clusters. there are four inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to four Se+1.25-, one S2-, and two I1- atoms to form a mixture of corner and face-sharing TaSe4SI2 pentagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.64–2.68 Å. The Ta–S bond length is 2.45 Å. There are one shorter (2.73 Å) and one longer (2.79 Å) Ta–I bond lengths. In the second Ta5+ site, Ta5+ is bonded to four Se+1.25-, one S2-, and two I1- atoms to form a mixture of corner and face-sharing TaSe4SI2 pentagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.66–2.68 Å. The Ta–S bond length is 2.47 Å. There are one shorter (2.74 Å) and one longer (2.77 Å) Ta–I bond lengths. In the third Ta5+ site, Ta5+ is bonded to four Se+1.25-, one S2-, and two I1- atoms to form a mixture of corner and face-sharing TaSe4SI2 pentagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.64–2.67 Å. The Ta–S bond length is 2.44 Å. There are one shorter (2.80 Å) and one longer (2.82 Å) Ta–I bond lengths. In the fourth Ta5+ site, Ta5+ is bonded to four Se+1.25-, one S2-, and two I1- atoms to form a mixture of corner and face-sharing TaSe4SI2 pentagonal bipyramids. There are one shorter (2.65 Å) and three longer (2.67 Å) Ta–Se bond lengths. The Ta–S bond length is 2.48 Å. There are one shorter (2.74 Å) and one longer (2.76 Å) Ta–I bond lengths. There are eight inequivalent Se+1.25- sites. In the first Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the second Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the third Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the fourth Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the fifth Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the sixth Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the seventh Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. In the eighth Se+1.25- site, Se+1.25- is bonded in a 2-coordinate geometry to two Ta5+ atoms. S2- is bonded in a distorted square co-planar geometry to four Ta5+ atoms. There are eight inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted single-bond geometry to one Ta5+ atom. In the second I1- site, I1- is bonded in a distorted single-bond geometry to one Ta5+ atom. In the third I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom. In the fourth I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom. In the fifth I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom. In the sixth I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom. In the seventh I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom. In the eighth I1- site, I1- is bonded in a single-bond geometry to one Ta5+ atom.