Materials Data on Bi4IBr3 by Materials Project
BiBiBr2Bi2IBr crystallizes in the orthorhombic Cmc2_1 space group. The structure is one-dimensional and consists of four bismuth molecules; four Bi2IBr ribbons oriented in the (1, 0, 0) direction; and four BiBr2 ribbons oriented in the (1, 0, 0) direction. In each Bi2IBr ribbon, there are two inequivalent Bi1+ sites. In the first Bi1+ site, Bi1+ is bonded in a distorted single-bond geometry to one I1- atom. The Bi–I bond length is 3.87 Å. In the second Bi1+ site, Bi1+ is bonded in a rectangular see-saw-like geometry to two equivalent I1- and two equivalent Br1- atoms. Both Bi–I bond lengths are 3.13 Å. Both Bi–Br bond lengths are 2.96 Å. I1- is bonded in a distorted L-shaped geometry to three Bi1+ atoms. Br1- is bonded in an L-shaped geometry to two equivalent Bi1+ atoms. In each BiBr2 ribbon, Bi1+ is bonded in a square co-planar geometry to four Br1- atoms. There are two shorter (2.95 Å) and two longer (2.96 Å) Bi–Br bond lengths. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Bi1+ atoms. In the second Br1- site, Br1- is bonded in an L-shaped geometry to two equivalent Bi1+ atoms.