Materials Data on Ta2Se8Br by Materials Project
Ta2Se8Br crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Ta+4.50+ sites. In the first Ta+4.50+ site, Ta+4.50+ is bonded to eight Se1- atoms to form face-sharing TaSe8 hexagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.57–2.80 Å. In the second Ta+4.50+ site, Ta+4.50+ is bonded to seven Se1- and one Br1- atom to form distorted face-sharing TaSe7Br hexagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.61–2.74 Å. The Ta–Br bond length is 2.66 Å. In the third Ta+4.50+ site, Ta+4.50+ is bonded to eight Se1- atoms to form face-sharing TaSe8 hexagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.59–2.77 Å. In the fourth Ta+4.50+ site, Ta+4.50+ is bonded to eight Se1- atoms to form face-sharing TaSe8 hexagonal bipyramids. There are a spread of Ta–Se bond distances ranging from 2.60–2.74 Å. There are sixteen inequivalent Se1- sites. In the first Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the second Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the third Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the fourth Se1- site, Se1- is bonded in a 1-coordinate geometry to one Ta+4.50+ atom. In the fifth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ and one Se1- atom. The Se–Se bond length is 2.39 Å. In the sixth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ and one Se1- atom. The Se–Se bond length is 2.40 Å. In the seventh Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the eighth Se1- site, Se1- is bonded in a 1-coordinate geometry to two Ta+4.50+, one Se1-, and one Br1- atom. The Se–Br bond length is 3.16 Å. In the ninth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the tenth Se1- site, Se1- is bonded in a 3-coordinate geometry to two Ta+4.50+ and one Br1- atom. The Se–Br bond length is 3.12 Å. In the eleventh Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+, one Se1-, and one Br1- atom. The Se–Se bond length is 2.41 Å. The Se–Br bond length is 3.10 Å. In the twelfth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the thirteenth Se1- site, Se1- is bonded in a 1-coordinate geometry to two Ta+4.50+, one Se1-, and one Br1- atom. The Se–Br bond length is 3.13 Å. In the fourteenth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ and one Se1- atom. In the fifteenth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. In the sixteenth Se1- site, Se1- is bonded in a 2-coordinate geometry to two Ta+4.50+ atoms. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 1-coordinate geometry to one Ta+4.50+ atom. In the second Br1- site, Br1- is bonded in a 4-coordinate geometry to four Se1- atoms.