Materials Data on Ba4Si21Au2 by Materials Project
Ba4Au2Si21 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to twenty Si+0.57- atoms. There are a spread of Ba–Si bond distances ranging from 3.32–3.46 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Si+0.57- atoms. There are a spread of Ba–Si bond distances ranging from 3.43–3.65 Å. In the third Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to ten Si+0.57- atoms. There are a spread of Ba–Si bond distances ranging from 3.43–3.73 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to twelve Si+0.57- atoms. There are a spread of Ba–Si bond distances ranging from 3.44–3.84 Å. There are two inequivalent Au2+ sites. In the first Au2+ site, Au2+ is bonded in a tetrahedral geometry to four Si+0.57- atoms. All Au–Si bond lengths are 2.49 Å. In the second Au2+ site, Au2+ is bonded in a tetrahedral geometry to four Si+0.57- atoms. There are two shorter (2.46 Å) and two longer (2.47 Å) Au–Si bond lengths. There are thirteen inequivalent Si+0.57- sites. In the first Si+0.57- site, Si+0.57- is bonded in a 7-coordinate geometry to three Ba2+ and four Si+0.57- atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.49 Å. In the second Si+0.57- site, Si+0.57- is bonded in a distorted single-bond geometry to three Ba2+, one Au2+, and two Si+0.57- atoms. Both Si–Si bond lengths are 2.41 Å. In the third Si+0.57- site, Si+0.57- is bonded in a 7-coordinate geometry to three Ba2+ and four Si+0.57- atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.47 Å. In the fourth Si+0.57- site, Si+0.57- is bonded in a distorted single-bond geometry to three Ba2+, one Au2+, and three Si+0.57- atoms. Both Si–Si bond lengths are 2.41 Å. In the fifth Si+0.57- site, Si+0.57- is bonded in a distorted single-bond geometry to three Ba2+, one Au2+, and two Si+0.57- atoms. Both Si–Si bond lengths are 2.41 Å. In the sixth Si+0.57- site, Si+0.57- is bonded in a distorted single-bond geometry to three Ba2+, one Au2+, and three Si+0.57- atoms. There are two shorter (2.40 Å) and one longer (2.49 Å) Si–Si bond lengths. In the seventh Si+0.57- site, Si+0.57- is bonded in a 7-coordinate geometry to three Ba2+ and four Si+0.57- atoms. There are two shorter (2.41 Å) and one longer (2.45 Å) Si–Si bond lengths. In the eighth Si+0.57- site, Si+0.57- is bonded in a distorted single-bond geometry to three Ba2+, one Au2+, and three Si+0.57- atoms. Both Si–Si bond lengths are 2.41 Å. In the ninth Si+0.57- site, Si+0.57- is bonded in a 5-coordinate geometry to one Ba2+ and four Si+0.57- atoms. The Si–Si bond length is 2.36 Å. In the tenth Si+0.57- site, Si+0.57- is bonded in a 8-coordinate geometry to four Ba2+ and four Si+0.57- atoms. The Si–Si bond length is 2.41 Å. In the eleventh Si+0.57- site, Si+0.57- is bonded in a 8-coordinate geometry to one Ba2+ and four Si+0.57- atoms. The Si–Si bond length is 2.38 Å. In the twelfth Si+0.57- site, Si+0.57- is bonded in a 8-coordinate geometry to one Ba2+ and four Si+0.57- atoms. In the thirteenth Si+0.57- site, Si+0.57- is bonded in a distorted tetrahedral geometry to four Si+0.57- atoms.