Materials Data on Ba4Si22Au by Materials Project
Ba4AuSi22 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. there are four inequivalent Ba sites. In the first Ba site, Ba is bonded in a 8-coordinate geometry to twenty Si atoms. There are a spread of Ba–Si bond distances ranging from 3.31–3.48 Å. In the second Ba site, Ba is bonded in a 9-coordinate geometry to one Au and fifteen Si atoms. The Ba–Au bond length is 3.56 Å. There are a spread of Ba–Si bond distances ranging from 3.45–3.82 Å. In the third Ba site, Ba is bonded in a 10-coordinate geometry to two equivalent Au and twelve Si atoms. Both Ba–Au bond lengths are 3.62 Å. There are a spread of Ba–Si bond distances ranging from 3.47–3.78 Å. In the fourth Ba site, Ba is bonded in a 9-coordinate geometry to one Au and nine Si atoms. The Ba–Au bond length is 3.59 Å. There are a spread of Ba–Si bond distances ranging from 3.45–3.73 Å. Au is bonded to four Ba and four Si atoms to form AuBa4Si4 tetrahedra that share corners with two equivalent AuBa4Si4 tetrahedra and corners with two equivalent SiBa2Si4 tetrahedra. There are one shorter (2.47 Å) and three longer (2.48 Å) Au–Si bond lengths. There are fourteen inequivalent Si sites. In the first Si site, Si is bonded in a distorted single-bond geometry to three Ba, one Au, and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.40–2.47 Å. In the second Si site, Si is bonded in a 7-coordinate geometry to three Ba and four Si atoms. There are three shorter (2.40 Å) and one longer (2.57 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a distorted single-bond geometry to three Ba, one Au, and three Si atoms. There are two shorter (2.41 Å) and one longer (2.50 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 7-coordinate geometry to three Ba and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.40–2.45 Å. In the fifth Si site, Si is bonded in a 7-coordinate geometry to three Ba and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.48 Å. In the sixth Si site, Si is bonded in a 7-coordinate geometry to three Ba and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.47 Å. In the seventh Si site, Si is bonded in a distorted single-bond geometry to three Ba, one Au, and three Si atoms. Both Si–Si bond lengths are 2.41 Å. In the eighth Si site, Si is bonded in a 7-coordinate geometry to three Ba and four Si atoms. There are two shorter (2.42 Å) and one longer (2.44 Å) Si–Si bond lengths. In the ninth Si site, Si is bonded in a 8-coordinate geometry to four Ba and four Si atoms. The Si–Si bond length is 2.38 Å. In the tenth Si site, Si is bonded in a 5-coordinate geometry to one Ba and four Si atoms. The Si–Si bond length is 2.34 Å. In the eleventh Si site, Si is bonded in a 8-coordinate geometry to one Ba and four Si atoms. The Si–Si bond length is 2.36 Å. In the twelfth Si site, Si is bonded in a 8-coordinate geometry to one Ba and four Si atoms. In the thirteenth Si site, Si is bonded to two equivalent Ba and four Si atoms to form distorted SiBa2Si4 tetrahedra that share corners with two equivalent AuBa4Si4 tetrahedra and corners with two equivalent SiBa2Si4 tetrahedra. In the fourteenth Si site, Si is bonded in a 4-coordinate geometry to four Ba and four Si atoms.