The material described by Al4Si19 is beta beryllia-like structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded to one Si(20), one Si(22), one Si(35), and one Si(37) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the second Al site, Al(2) is bonded to one Si(24), one Si(25), one Si(33), and one Si(34) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the third Al site, Al(3) is bonded to one Si(26), one Si(28), one Si(30), and one Si(31) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fourth Al site, Al(4) is bonded to one Si(1), one Si(15), one Si(20), and one Si(4) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the fifth Al site, Al(5) is bonded to one Si(15), one Si(2), one Si(25), and one Si(5) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the sixth Al site, Al(6) is bonded to one Si(12), one Si(28), one Si(3), and one Si(5) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the seventh Al site, Al(7) is bonded to one Si(10), one Si(17), one Si(3), and one Si(31) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the eighth Al site, Al(8) is bonded to one Si(19), one Si(2), one Si(34), and one Si(9) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. There are thirty-eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one Al(4), one Si(21), one Si(36), and one Si(38) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the second Si site, Si(2) is bonded to one Al(5), one Al(8), one Si(23), and one Si(32) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the third Si site, Si(3) is bonded to one Al(6), one Al(7), one Si(27), and one Si(29) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the fourth Si site, Si(4) is bonded to one Al(4), one Si(23), one Si(26), and one Si(9) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the fifth Si site, Si(5) is bonded to one Al(5), one Al(6), one Si(20), and one Si(8) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(32)Si4 tetrahedra. In the sixth Si site, Si(6) is bonded to one Si(10), one Si(21), one Si(25), and one Si(27) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the seventh Si site, Si(7) is bonded to one Si(11), one Si(22), one Si(24), and one Si(28) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(23)Si4 tetrahedra. In the eighth Si site, Si(8) is bonded to one Si(29), one Si(32), one Si(35), and one Si(5) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the ninth Si site, Si(9) is bonded to one Al(8), one Si(30), one Si(38), and one Si(4) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the tenth Si site, Si(10) is bonded to one Al(7), one Si(34), one Si(36), and one Si(6) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(27)Si4 tetrahedra. In the eleventh Si site, Si(11) is bonded to one Si(31), one Si(33), one Si(37), and one Si(7) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the twelfth Si site, Si(12) is bonded to one Al(6), one Si(17), one Si(22), and one Si(25) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirteenth Si site, Si(13) is bonded to one Si(16), one Si(21), one Si(24), and one Si(26) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fourteenth Si site, Si(14) is bonded to one Si(18), one Si(20), one Si(23), and one Si(28) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fifteenth Si site, Si(15) is bonded to one Al(4), one Al(5), one Si(19), and one Si(27) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the sixteenth Si site, Si(16) is bonded to one Si(13), one Si(31), one Si(34), and one Si(38) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra, and  a cornercorner with one Si(21)Si4 tetrahedra. In the seventeenth Si site, Si(17) is bonded to one Al(7), one Si(12), one Si(33), and one Si(35) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the eighteenth Si site, Si(18) is bonded to one Si(14), one Si(30), one Si(32), and one Si(37) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the nineteenth Si site, Si(19) is bonded to one Al(8), one Si(15), one Si(29), and one Si(36) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the twentieth Si site, Si(20) is bonded to one Al(1), one Al(4), one Si(14), and one Si(5) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the twenty-first Si site, Si(21) is bonded to one Si(1), one Si(13), one Si(22), and one Si(6) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the twenty-second Si site, Si(22) is bonded to one Al(1), one Si(12), one Si(21), and one Si(7) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the twenty-third Si site, Si(23) is bonded to one Si(14), one Si(2), one Si(24), and one Si(4) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the twenty-fourth Si site, Si(24) is bonded to one Al(2), one Si(13), one Si(23), and one Si(7) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra, and  a cornercorner with one Si(21)Si4 tetrahedra. In the twenty-fifth Si site, Si(25) is bonded to one Al(2), one Al(5), one Si(12), and one Si(6) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(27)Si4 tetrahedra. In the twenty-sixth Si site, Si(26) is bonded to one Al(3), one Si(13), one Si(27), and one Si(4) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the twenty-seventh Si site, Si(27) is bonded to one Si(15), one Si(26), one Si(3), and one Si(6) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the twenty-eighth Si site, Si(28) is bonded to one Al(3), one Al(6), one Si(14), and one Si(7) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(23)Si4 tetrahedra. In the twenty-ninth Si site, Si(29) is bonded to one Si(19), one Si(3), one Si(30), and one Si(8) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the thirtieth Si site, Si(30) is bonded to one Al(3), one Si(18), one Si(29), and one Si(9) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-first Si site, Si(31) is bonded to one Al(3), one Al(7), one Si(11), and one Si(16) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirty-second Si site, Si(32) is bonded to one Si(18), one Si(2), one Si(33), and one Si(8) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the thirty-third Si site, Si(33) is bonded to one Al(2), one Si(11), one Si(17), and one Si(32) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-fourth Si site, Si(34) is bonded to one Al(2), one Al(8), one Si(10), and one Si(16) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the thirty-fifth Si site, Si(35) is bonded to one Al(1), one Si(17), one Si(36), and one Si(8) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(32)Si4 tetrahedra. In the thirty-sixth Si site, Si(36) is bonded to one Si(1), one Si(10), one Si(19), and one Si(35) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-seventh Si site, Si(37) is bonded to one Al(1), one Si(11), one Si(18), and one Si(38) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirty-eighth Si site, Si(38) is bonded to one Si(1), one Si(16), one Si(37), and one Si(9) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al4Si19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.335
_cell_length_b   10.393
_cell_length_c   10.473
_cell_angle_alpha   89.025
_cell_angle_beta   89.444
_cell_angle_gamma   89.371
_symmetry_Int_Tables_number   1
_cell_volume   1124.731
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Al  Al0  1  0.258  0.502  0.001  1.0
  Al  Al1  1  1.000  0.754  0.506  1.0
  Al  Al2  1  0.503  0.002  0.751  1.0
  Al  Al3  1  0.882  0.311  0.997  1.0
  Al  Al4  1  0.998  0.119  0.312  1.0
  Al  Al5  1  0.306  0.997  0.118  1.0
  Al  Al6  1  0.499  0.810  0.386  1.0
  Al  Al7  1  0.808  0.380  0.497  1.0
  Si  Si8  1  0.744  0.508  0.999  1.0
  Si  Si9  1  0.012  0.251  0.507  1.0
  Si  Si10  1  0.504  0.009  0.252  1.0
  Si  Si11  1  0.815  0.175  0.812  1.0
  Si  Si12  1  0.190  0.204  0.180  1.0
  Si  Si13  1  0.815  0.813  0.177  1.0
  Si  Si14  1  0.180  0.816  0.816  1.0
  Si  Si15  1  0.319  0.325  0.320  1.0
  Si  Si16  1  0.678  0.315  0.692  1.0
  Si  Si17  1  0.692  0.677  0.313  1.0
  Si  Si18  1  0.316  0.681  0.686  1.0
  Si  Si19  1  0.172  0.800  0.183  1.0
  Si  Si20  1  0.817  0.819  0.814  1.0
  Si  Si21  1  0.186  0.182  0.815  1.0
  Si  Si22  1  0.804  0.178  0.181  1.0
  Si  Si23  1  0.682  0.686  0.686  1.0
  Si  Si24  1  0.311  0.674  0.319  1.0
  Si  Si25  1  0.322  0.318  0.685  1.0
  Si  Si26  1  0.680  0.314  0.310  1.0
  Si  Si27  1  0.120  0.307  0.992  1.0
  Si  Si28  1  0.877  0.693  0.995  1.0
  Si  Si29  1  0.106  0.692  0.996  1.0
  Si  Si30  1  0.003  0.118  0.694  1.0
  Si  Si31  1  0.000  0.891  0.696  1.0
  Si  Si32  1  0.993  0.879  0.296  1.0
  Si  Si33  1  0.697  0.997  0.889  1.0
  Si  Si34  1  0.691  0.997  0.116  1.0
  Si  Si35  1  0.300  0.995  0.883  1.0
  Si  Si36  1  0.500  0.198  0.382  1.0
  Si  Si37  1  0.502  0.199  0.610  1.0
  Si  Si38  1  0.497  0.803  0.619  1.0
  Si  Si39  1  0.197  0.382  0.506  1.0
  Si  Si40  1  0.195  0.610  0.507  1.0
  Si  Si41  1  0.802  0.619  0.502  1.0
  Si  Si42  1  0.392  0.503  0.197  1.0
  Si  Si43  1  0.621  0.502  0.191  1.0
  Si  Si44  1  0.392  0.498  0.803  1.0
  Si  Si45  1  0.620  0.500  0.809  1.0
[/CIF]
.
The material described by Al4Si19 is beta beryllia-like structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded to one Si(20), one Si(22), one Si(35), and one Si(37) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the second Al site, Al(2) is bonded to one Si(24), one Si(25), one Si(33), and one Si(34) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the third Al site, Al(3) is bonded to one Si(26), one Si(28), one Si(30), and one Si(31) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fourth Al site, Al(4) is bonded to one Si(1), one Si(15), one Si(20), and one Si(4) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the fifth Al site, Al(5) is bonded to one Si(15), one Si(2), one Si(25), and one Si(5) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the sixth Al site, Al(6) is bonded to one Si(12), one Si(28), one Si(3), and one Si(5) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the seventh Al site, Al(7) is bonded to one Si(10), one Si(17), one Si(3), and one Si(31) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the eighth Al site, Al(8) is bonded to one Si(19), one Si(2), one Si(34), and one Si(9) atom to form AlSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. There are thirty-eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one Al(4), one Si(21), one Si(36), and one Si(38) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the second Si site, Si(2) is bonded to one Al(5), one Al(8), one Si(23), and one Si(32) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the third Si site, Si(3) is bonded to one Al(6), one Al(7), one Si(27), and one Si(29) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the fourth Si site, Si(4) is bonded to one Al(4), one Si(23), one Si(26), and one Si(9) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the fifth Si site, Si(5) is bonded to one Al(5), one Al(6), one Si(20), and one Si(8) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(32)Si4 tetrahedra. In the sixth Si site, Si(6) is bonded to one Si(10), one Si(21), one Si(25), and one Si(27) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the seventh Si site, Si(7) is bonded to one Si(11), one Si(22), one Si(24), and one Si(28) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(23)Si4 tetrahedra. In the eighth Si site, Si(8) is bonded to one Si(29), one Si(32), one Si(35), and one Si(5) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the ninth Si site, Si(9) is bonded to one Al(8), one Si(30), one Si(38), and one Si(4) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the tenth Si site, Si(10) is bonded to one Al(7), one Si(34), one Si(36), and one Si(6) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(27)Si4 tetrahedra. In the eleventh Si site, Si(11) is bonded to one Si(31), one Si(33), one Si(37), and one Si(7) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(38)Si4 tetrahedra. In the twelfth Si site, Si(12) is bonded to one Al(6), one Si(17), one Si(22), and one Si(25) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirteenth Si site, Si(13) is bonded to one Si(16), one Si(21), one Si(24), and one Si(26) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fourteenth Si site, Si(14) is bonded to one Si(18), one Si(20), one Si(23), and one Si(28) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the fifteenth Si site, Si(15) is bonded to one Al(4), one Al(5), one Si(19), and one Si(27) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the sixteenth Si site, Si(16) is bonded to one Si(13), one Si(31), one Si(34), and one Si(38) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra, and  a cornercorner with one Si(21)Si4 tetrahedra. In the seventeenth Si site, Si(17) is bonded to one Al(7), one Si(12), one Si(33), and one Si(35) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the eighteenth Si site, Si(18) is bonded to one Si(14), one Si(30), one Si(32), and one Si(37) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the nineteenth Si site, Si(19) is bonded to one Al(8), one Si(15), one Si(29), and one Si(36) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the twentieth Si site, Si(20) is bonded to one Al(1), one Al(4), one Si(14), and one Si(5) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the twenty-first Si site, Si(21) is bonded to one Si(1), one Si(13), one Si(22), and one Si(6) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the twenty-second Si site, Si(22) is bonded to one Al(1), one Si(12), one Si(21), and one Si(7) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the twenty-third Si site, Si(23) is bonded to one Si(14), one Si(2), one Si(24), and one Si(4) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the twenty-fourth Si site, Si(24) is bonded to one Al(2), one Si(13), one Si(23), and one Si(7) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra, and  a cornercorner with one Si(21)Si4 tetrahedra. In the twenty-fifth Si site, Si(25) is bonded to one Al(2), one Al(5), one Si(12), and one Si(6) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(27)Si4 tetrahedra. In the twenty-sixth Si site, Si(26) is bonded to one Al(3), one Si(13), one Si(27), and one Si(4) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the twenty-seventh Si site, Si(27) is bonded to one Si(15), one Si(26), one Si(3), and one Si(6) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the twenty-eighth Si site, Si(28) is bonded to one Al(3), one Al(6), one Si(14), and one Si(7) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra, and  a cornercorner with one Si(23)Si4 tetrahedra. In the twenty-ninth Si site, Si(29) is bonded to one Si(19), one Si(3), one Si(30), and one Si(8) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(3)Si4 tetrahedra,  a cornercorner with one Al(6)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(27)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. In the thirtieth Si site, Si(30) is bonded to one Al(3), one Si(18), one Si(29), and one Si(9) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-first Si site, Si(31) is bonded to one Al(3), one Al(7), one Si(11), and one Si(16) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Si(28)Al2Si2 tetrahedra,  a cornercorner with one Si(3)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(26)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirty-second Si site, Si(32) is bonded to one Si(18), one Si(2), one Si(33), and one Si(8) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(2)Si4 tetrahedra,  a cornercorner with one Al(5)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(23)Si4 tetrahedra, and  a cornercorner with one Si(29)Si4 tetrahedra. In the thirty-third Si site, Si(33) is bonded to one Al(2), one Si(11), one Si(17), and one Si(32) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(7)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-fourth Si site, Si(34) is bonded to one Al(2), one Al(8), one Si(10), and one Si(16) atom to form SiAl2Si2 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(2)Al2Si2 tetrahedra,  a cornercorner with one Si(25)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(24)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(36)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra, and  a cornercorner with one Si(6)Si4 tetrahedra. In the thirty-fifth Si site, Si(35) is bonded to one Al(1), one Si(17), one Si(36), and one Si(8) atom to form distorted SiAlSi3 tetrahedra that share  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(5)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(10)AlSi3 tetrahedra,  a cornercorner with one Si(12)AlSi3 tetrahedra,  a cornercorner with one Si(19)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(37)AlSi3 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra, and  a cornercorner with one Si(32)Si4 tetrahedra. In the thirty-sixth Si site, Si(36) is bonded to one Si(1), one Si(10), one Si(19), and one Si(35) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(7)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(15)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(17)AlSi3 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra,  a cornercorner with one Si(29)Si4 tetrahedra,  a cornercorner with one Si(38)Si4 tetrahedra,  a cornercorner with one Si(6)Si4 tetrahedra, and  a cornercorner with one Si(8)Si4 tetrahedra. In the thirty-seventh Si site, Si(37) is bonded to one Al(1), one Si(11), one Si(18), and one Si(38) atom to form SiAlSi3 tetrahedra that share  a cornercorner with one Si(20)Al2Si2 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(1)AlSi3 tetrahedra,  a cornercorner with one Si(22)AlSi3 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(33)AlSi3 tetrahedra,  a cornercorner with one Si(35)AlSi3 tetrahedra,  a cornercorner with one Si(9)AlSi3 tetrahedra,  a cornercorner with one Si(14)Si4 tetrahedra,  a cornercorner with one Si(16)Si4 tetrahedra,  a cornercorner with one Si(32)Si4 tetrahedra, and  a cornercorner with one Si(7)Si4 tetrahedra. In the thirty-eighth Si site, Si(38) is bonded to one Si(1), one Si(16), one Si(37), and one Si(9) atom to form SiSi4 tetrahedra that share  a cornercorner with one Al(1)Si4 tetrahedra,  a cornercorner with one Al(4)Si4 tetrahedra,  a cornercorner with one Al(8)Si4 tetrahedra,  a cornercorner with one Si(31)Al2Si2 tetrahedra,  a cornercorner with one Si(34)Al2Si2 tetrahedra,  a cornercorner with one Si(30)AlSi3 tetrahedra,  a cornercorner with one Si(4)AlSi3 tetrahedra,  a cornercorner with one Si(11)Si4 tetrahedra,  a cornercorner with one Si(13)Si4 tetrahedra,  a cornercorner with one Si(18)Si4 tetrahedra,  a cornercorner with one Si(21)Si4 tetrahedra, and  a cornercorner with one Si(36)Si4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al4Si19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.335
_cell_length_b   10.393
_cell_length_c   10.473
_cell_angle_alpha   89.025
_cell_angle_beta   89.444
_cell_angle_gamma   89.371
_symmetry_Int_Tables_number   1
_cell_volume   1124.731
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Al  Al0  1  0.258  0.502  0.001  1.0
  Al  Al1  1  1.000  0.754  0.506  1.0
  Al  Al2  1  0.503  0.002  0.751  1.0
  Al  Al3  1  0.882  0.311  0.997  1.0
  Al  Al4  1  0.998  0.119  0.312  1.0
  Al  Al5  1  0.306  0.997  0.118  1.0
  Al  Al6  1  0.499  0.810  0.386  1.0
  Al  Al7  1  0.808  0.380  0.497  1.0
  Si  Si8  1  0.744  0.508  0.999  1.0
  Si  Si9  1  0.012  0.251  0.507  1.0
  Si  Si10  1  0.504  0.009  0.252  1.0
  Si  Si11  1  0.815  0.175  0.812  1.0
  Si  Si12  1  0.190  0.204  0.180  1.0
  Si  Si13  1  0.815  0.813  0.177  1.0
  Si  Si14  1  0.180  0.816  0.816  1.0
  Si  Si15  1  0.319  0.325  0.320  1.0
  Si  Si16  1  0.678  0.315  0.692  1.0
  Si  Si17  1  0.692  0.677  0.313  1.0
  Si  Si18  1  0.316  0.681  0.686  1.0
  Si  Si19  1  0.172  0.800  0.183  1.0
  Si  Si20  1  0.817  0.819  0.814  1.0
  Si  Si21  1  0.186  0.182  0.815  1.0
  Si  Si22  1  0.804  0.178  0.181  1.0
  Si  Si23  1  0.682  0.686  0.686  1.0
  Si  Si24  1  0.311  0.674  0.319  1.0
  Si  Si25  1  0.322  0.318  0.685  1.0
  Si  Si26  1  0.680  0.314  0.310  1.0
  Si  Si27  1  0.120  0.307  0.992  1.0
  Si  Si28  1  0.877  0.693  0.995  1.0
  Si  Si29  1  0.106  0.692  0.996  1.0
  Si  Si30  1  0.003  0.118  0.694  1.0
  Si  Si31  1  0.000  0.891  0.696  1.0
  Si  Si32  1  0.993  0.879  0.296  1.0
  Si  Si33  1  0.697  0.997  0.889  1.0
  Si  Si34  1  0.691  0.997  0.116  1.0
  Si  Si35  1  0.300  0.995  0.883  1.0
  Si  Si36  1  0.500  0.198  0.382  1.0
  Si  Si37  1  0.502  0.199  0.610  1.0
  Si  Si38  1  0.497  0.803  0.619  1.0
  Si  Si39  1  0.197  0.382  0.506  1.0
  Si  Si40  1  0.195  0.610  0.507  1.0
  Si  Si41  1  0.802  0.619  0.502  1.0
  Si  Si42  1  0.392  0.503  0.197  1.0
  Si  Si43  1  0.621  0.502  0.191  1.0
  Si  Si44  1  0.392  0.498  0.803  1.0
  Si  Si45  1  0.620  0.500  0.809  1.0
[/CIF]
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