Materials Data on Ba4Si3Br2 by Materials Project
Ba4Si3Br2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of eight hydrobromic acid molecules and one Ba4Si3 sheet oriented in the (0, 0, 1) direction. In the Ba4Si3 sheet, there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are a spread of Ba–Si bond distances ranging from 3.33–3.71 Å. In the second Ba2+ site, Ba2+ is bonded in a 3-coordinate geometry to four Si4- atoms. There are a spread of Ba–Si bond distances ranging from 3.37–3.81 Å. In the third Ba2+ site, Ba2+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are a spread of Ba–Si bond distances ranging from 3.51–3.67 Å. In the fourth Ba2+ site, Ba2+ is bonded in a distorted T-shaped geometry to three Si4- atoms. There are a spread of Ba–Si bond distances ranging from 3.25–3.51 Å. There are three inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 10-coordinate geometry to eight Ba2+ and two Si4- atoms. There are one shorter (2.41 Å) and one longer (2.43 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Ba2+ and two Si4- atoms. The Si–Si bond length is 2.48 Å. In the third Si4- site, Si4- is bonded in a 7-coordinate geometry to five Ba2+ and two Si4- atoms.