Ba8Au3Si43 crystallizes in the trigonal R32 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 20-coordinate geometry to one Si(1), one Si(2), three equivalent Si(3), three equivalent Si(4), three equivalent Si(5), three equivalent Si(6), three equivalent Si(7), and three equivalent Si(8) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent Au(1), two equivalent Si(1), two equivalent Si(5), two equivalent Si(6), two equivalent Si(7), two equivalent Si(8), two equivalent Si(9), and four equivalent Si(4) atoms. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent Au(1), two equivalent Si(4), two equivalent Si(5), two equivalent Si(6), two equivalent Si(7), two equivalent Si(8), and two equivalent Si(9) atoms. Au(1) is bonded to two equivalent Ba(2), two equivalent Ba(3), two equivalent Si(5), and two equivalent Si(8) atoms to form AuBa4Si4 tetrahedra that share corners with four equivalent Au(1)Ba4Si4 tetrahedra, corners with four equivalent Si(9)Ba4Si4 tetrahedra, and edges with two equivalent Si(9)Ba4Si4 tetrahedra. There are nine inequivalent Si sites. In the first Si site, Si(9) is bonded to two equivalent Ba(2), two equivalent Ba(3), two equivalent Si(6), and two equivalent Si(7) atoms to form distorted SiBa4Si4 tetrahedra that share corners with four equivalent Au(1)Ba4Si4 tetrahedra, corners with four equivalent Si(9)Ba4Si4 tetrahedra, and edges with two equivalent Au(1)Ba4Si4 tetrahedra. In the second Si site, Si(5) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), one Au(1), one Si(1), one Si(4), and one Si(7) atom. In the third Si site, Si(6) is bonded in a 7-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Si(2), one Si(3), one Si(8), and one Si(9) atom. In the fourth Si site, Si(7) is bonded in a 7-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Si(3), one Si(4), one Si(5), and one Si(9) atom. In the fifth Si site, Si(8) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), one Au(1), one Si(3), one Si(4), and one Si(6) atom. In the sixth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to one Ba(1), three equivalent Ba(2), one Si(1), and three equivalent Si(5) atoms. In the seventh Si site, Si(2) is bonded in a 5-coordinate geometry to one Ba(1), one Si(2), and three equivalent Si(6) atoms. In the eighth Si site, Si(3) is bonded in a 5-coordinate geometry to one Ba(1), one Si(3), one Si(6), one Si(7), and one Si(8) atom. In the ninth Si site, Si(4) is bonded in a 8-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), one Si(4), one Si(5), one Si(7), and one Si(8) atom.
Ba8Au3Si43 crystallizes in the trigonal R32 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 20-coordinate geometry to one Si(1), one Si(2), three equivalent Si(3), three equivalent Si(4), three equivalent Si(5), three equivalent Si(6), three equivalent Si(7), and three equivalent Si(8) atoms. The Ba(1)-Si(1) bond length is 3.30 Å. The Ba(1)-Si(2) bond length is 3.36 Å. All Ba(1)-Si(3) bond lengths are 3.35 Å. All Ba(1)-Si(4) bond lengths are 3.33 Å. All Ba(1)-Si(5) bond lengths are 3.39 Å. All Ba(1)-Si(6) bond lengths are 3.44 Å. All Ba(1)-Si(7) bond lengths are 3.41 Å. All Ba(1)-Si(8) bond lengths are 3.42 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent Au(1), two equivalent Si(1), two equivalent Si(5), two equivalent Si(6), two equivalent Si(7), two equivalent Si(8), two equivalent Si(9), and four equivalent Si(4) atoms. Both Ba(2)-Au(1) bond lengths are 3.60 Å. Both Ba(2)-Si(1) bond lengths are 3.72 Å. Both Ba(2)-Si(5) bond lengths are 3.44 Å. Both Ba(2)-Si(6) bond lengths are 3.64 Å. Both Ba(2)-Si(7) bond lengths are 3.53 Å. Both Ba(2)-Si(8) bond lengths are 3.56 Å. Both Ba(2)-Si(9) bond lengths are 3.76 Å. There are two shorter (3.85 Å) and two longer (3.88 Å) Ba(2)-Si(4) bond lengths. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent Au(1), two equivalent Si(4), two equivalent Si(5), two equivalent Si(6), two equivalent Si(7), two equivalent Si(8), and two equivalent Si(9) atoms. Both Ba(3)-Au(1) bond lengths are 3.61 Å. Both Ba(3)-Si(4) bond lengths are 3.72 Å. Both Ba(3)-Si(5) bond lengths are 3.42 Å. Both Ba(3)-Si(6) bond lengths are 3.61 Å. Both Ba(3)-Si(7) bond lengths are 3.50 Å. Both Ba(3)-Si(8) bond lengths are 3.53 Å. Both Ba(3)-Si(9) bond lengths are 3.78 Å. Au(1) is bonded to two equivalent Ba(2), two equivalent Ba(3), two equivalent Si(5), and two equivalent Si(8) atoms to form AuBa4Si4 tetrahedra that share corners with four equivalent Au(1)Ba4Si4 tetrahedra, corners with four equivalent Si(9)Ba4Si4 tetrahedra, and edges with two equivalent Si(9)Ba4Si4 tetrahedra. Both Au(1)-Si(5) bond lengths are 2.45 Å. Both Au(1)-Si(8) bond lengths are 2.45 Å. There are nine inequivalent Si sites. In the first Si site, Si(9) is bonded to two equivalent Ba(2), two equivalent Ba(3), two equivalent Si(6), and two equivalent Si(7) atoms to form distorted SiBa4Si4 tetrahedra that share corners with four equivalent Au(1)Ba4Si4 tetrahedra, corners with four equivalent Si(9)Ba4Si4 tetrahedra, and edges with two equivalent Au(1)Ba4Si4 tetrahedra. Both Si(9)-Si(6) bond lengths are 2.43 Å. Both Si(9)-Si(7) bond lengths are 2.44 Å. In the second Si site, Si(5) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), one Au(1), one Si(1), one Si(4), and one Si(7) atom. The Si(5)-Si(1) bond length is 2.39 Å. The Si(5)-Si(4) bond length is 2.40 Å. The Si(5)-Si(7) bond length is 2.50 Å. In the third Si site, Si(6) is bonded in a 7-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Si(2), one Si(3), one Si(8), and one Si(9) atom. The Si(6)-Si(2) bond length is 2.40 Å. The Si(6)-Si(3) bond length is 2.41 Å. The Si(6)-Si(8) bond length is 2.45 Å. In the fourth Si site, Si(7) is bonded in a 7-coordinate geometry to one Ba(1), one Ba(2), one Ba(3), one Si(3), one Si(4), one Si(5), and one Si(9) atom. The Si(7)-Si(3) bond length is 2.41 Å. The Si(7)-Si(4) bond length is 2.39 Å. In the fifth Si site, Si(8) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), one Au(1), one Si(3), one Si(4), and one Si(6) atom. The Si(8)-Si(3) bond length is 2.40 Å. The Si(8)-Si(4) bond length is 2.40 Å. In the sixth Si site, Si(1) is bonded in a distorted body-centered cubic geometry to one Ba(1), three equivalent Ba(2), one Si(1), and three equivalent Si(5) atoms. The Si(1)-Si(1) bond length is 2.40 Å. In the seventh Si site, Si(2) is bonded in a 5-coordinate geometry to one Ba(1), one Si(2), and three equivalent Si(6) atoms. The Si(2)-Si(2) bond length is 2.32 Å. In the eighth Si site, Si(3) is bonded in a 5-coordinate geometry to one Ba(1), one Si(3), one Si(6), one Si(7), and one Si(8) atom. The Si(3)-Si(3) bond length is 2.33 Å. In the ninth Si site, Si(4) is bonded in a 8-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), one Si(4), one Si(5), one Si(7), and one Si(8) atom. The Si(4)-Si(4) bond length is 2.36 Å.