Ti20(AlSi3)3 crystallizes in the monoclinic Pm space group. There are sixteen inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 8-coordinate geometry to two equivalent Ti(1), one Al(2), one Al(3), one Si(2), one Si(5), one Si(6), and one Si(8) atom. In the second Ti site, Ti(2) is bonded in a 8-coordinate geometry to two equivalent Ti(2), one Al(1), one Si(1), one Si(3), one Si(4), one Si(7), and one Si(9) atom. In the third Ti site, Ti(3) is bonded in a 8-coordinate geometry to two equivalent Ti(3), one Al(1), one Al(3), one Si(2), one Si(4), one Si(6), and one Si(8) atom. In the fourth Ti site, Ti(4) is bonded in a 8-coordinate geometry to two equivalent Ti(4), one Al(2), one Si(1), one Si(3), one Si(5), one Si(7), and one Si(9) atom. In the fifth Ti site, Ti(5) is bonded in a 5-coordinate geometry to one Al(2), one Si(1), one Si(2), and two equivalent Si(5) atoms. In the sixth Ti site, Ti(6) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Si(3), and two equivalent Si(4) atoms. In the seventh Ti site, Ti(7) is bonded in a 5-coordinate geometry to one Al(2), one Al(3), one Si(2), and two equivalent Si(6) atoms. In the eighth Ti site, Ti(8) is bonded in a 5-coordinate geometry to one Al(1), one Si(1), one Si(3), and two equivalent Si(7) atoms. In the ninth Ti site, Ti(9) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Si(2), and two equivalent Si(8) atoms. In the tenth Ti site, Ti(10) is bonded in a 5-coordinate geometry to one Al(2), one Si(1), one Si(3), and two equivalent Si(9) atoms. In the eleventh Ti site, Ti(11) is bonded in a 5-coordinate geometry to two equivalent Al(2), one Si(5), one Si(6), and one Si(9) atom. In the twelfth Ti site, Ti(12) is bonded in a 5-coordinate geometry to two equivalent Al(1), one Si(4), one Si(7), and one Si(8) atom. In the thirteenth Ti site, Ti(13) is bonded in a 5-coordinate geometry to two equivalent Al(3), one Si(4), one Si(6), and one Si(8) atom. In the fourteenth Ti site, Ti(14) is bonded in a 5-coordinate geometry to one Si(5), one Si(7), one Si(9), and two equivalent Si(1) atoms. In the fifteenth Ti site, Ti(15) is bonded in a 5-coordinate geometry to one Si(5), one Si(6), one Si(8), and two equivalent Si(2) atoms. In the sixteenth Ti site, Ti(16) is bonded in a 5-coordinate geometry to one Si(4), one Si(7), one Si(9), and two equivalent Si(3) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to one Ti(6), one Ti(8), one Ti(9), two equivalent Ti(12), two equivalent Ti(2), and two equivalent Ti(3) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(5), one Ti(7), two equivalent Ti(1), two equivalent Ti(11), and two equivalent Ti(4) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to one Ti(6), one Ti(7), one Ti(9), two equivalent Ti(1), two equivalent Ti(13), and two equivalent Ti(3) atoms. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(5), one Ti(8), two equivalent Ti(14), two equivalent Ti(2), and two equivalent Ti(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Ti(5), one Ti(7), one Ti(9), two equivalent Ti(1), two equivalent Ti(15), and two equivalent Ti(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(6), one Ti(8), two equivalent Ti(16), two equivalent Ti(2), and two equivalent Ti(4) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(13), one Ti(16), two equivalent Ti(2), two equivalent Ti(3), and two equivalent Ti(6) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(14), one Ti(15), two equivalent Ti(1), two equivalent Ti(4), and two equivalent Ti(5) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(13), one Ti(15), two equivalent Ti(1), two equivalent Ti(3), and two equivalent Ti(7) atoms. In the seventh Si site, Si(7) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(14), one Ti(16), two equivalent Ti(2), two equivalent Ti(4), and two equivalent Ti(8) atoms. In the eighth Si site, Si(8) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(13), one Ti(15), two equivalent Ti(1), two equivalent Ti(3), and two equivalent Ti(9) atoms. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(14), one Ti(16), two equivalent Ti(10), two equivalent Ti(2), and two equivalent Ti(4) atoms.
Ti20(AlSi3)3 crystallizes in the monoclinic Pm space group. There are sixteen inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 8-coordinate geometry to two equivalent Ti(1), one Al(2), one Al(3), one Si(2), one Si(5), one Si(6), and one Si(8) atom. There is one shorter (2.55 Å) and one longer (2.62 Å) Ti(1)-Ti(1) bond length. The Ti(1)-Al(2) bond length is 2.69 Å. The Ti(1)-Al(3) bond length is 2.69 Å. The Ti(1)-Si(2) bond length is 2.63 Å. The Ti(1)-Si(5) bond length is 2.65 Å. The Ti(1)-Si(6) bond length is 2.67 Å. The Ti(1)-Si(8) bond length is 2.63 Å. In the second Ti site, Ti(2) is bonded in a 8-coordinate geometry to two equivalent Ti(2), one Al(1), one Si(1), one Si(3), one Si(4), one Si(7), and one Si(9) atom. There is one shorter (2.57 Å) and one longer (2.60 Å) Ti(2)-Ti(2) bond length. The Ti(2)-Al(1) bond length is 2.69 Å. The Ti(2)-Si(1) bond length is 2.65 Å. The Ti(2)-Si(3) bond length is 2.64 Å. The Ti(2)-Si(4) bond length is 2.68 Å. The Ti(2)-Si(7) bond length is 2.66 Å. The Ti(2)-Si(9) bond length is 2.64 Å. In the third Ti site, Ti(3) is bonded in a 8-coordinate geometry to two equivalent Ti(3), one Al(1), one Al(3), one Si(2), one Si(4), one Si(6), and one Si(8) atom. There is one shorter (2.55 Å) and one longer (2.62 Å) Ti(3)-Ti(3) bond length. The Ti(3)-Al(1) bond length is 2.69 Å. The Ti(3)-Al(3) bond length is 2.68 Å. The Ti(3)-Si(2) bond length is 2.64 Å. The Ti(3)-Si(4) bond length is 2.69 Å. The Ti(3)-Si(6) bond length is 2.65 Å. The Ti(3)-Si(8) bond length is 2.63 Å. In the fourth Ti site, Ti(4) is bonded in a 8-coordinate geometry to two equivalent Ti(4), one Al(2), one Si(1), one Si(3), one Si(5), one Si(7), and one Si(9) atom. There is one shorter (2.57 Å) and one longer (2.60 Å) Ti(4)-Ti(4) bond length. The Ti(4)-Al(2) bond length is 2.69 Å. The Ti(4)-Si(1) bond length is 2.64 Å. The Ti(4)-Si(3) bond length is 2.64 Å. The Ti(4)-Si(5) bond length is 2.66 Å. The Ti(4)-Si(7) bond length is 2.63 Å. The Ti(4)-Si(9) bond length is 2.65 Å. In the fifth Ti site, Ti(5) is bonded in a 5-coordinate geometry to one Al(2), one Si(1), one Si(2), and two equivalent Si(5) atoms. The Ti(5)-Al(2) bond length is 2.75 Å. The Ti(5)-Si(1) bond length is 2.57 Å. The Ti(5)-Si(2) bond length is 2.58 Å. Both Ti(5)-Si(5) bond lengths are 2.82 Å. In the sixth Ti site, Ti(6) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Si(3), and two equivalent Si(4) atoms. The Ti(6)-Al(1) bond length is 2.74 Å. The Ti(6)-Al(3) bond length is 2.65 Å. The Ti(6)-Si(3) bond length is 2.56 Å. Both Ti(6)-Si(4) bond lengths are 2.82 Å. In the seventh Ti site, Ti(7) is bonded in a 5-coordinate geometry to one Al(2), one Al(3), one Si(2), and two equivalent Si(6) atoms. The Ti(7)-Al(2) bond length is 2.63 Å. The Ti(7)-Al(3) bond length is 2.74 Å. The Ti(7)-Si(2) bond length is 2.55 Å. Both Ti(7)-Si(6) bond lengths are 2.83 Å. In the eighth Ti site, Ti(8) is bonded in a 5-coordinate geometry to one Al(1), one Si(1), one Si(3), and two equivalent Si(7) atoms. The Ti(8)-Al(1) bond length is 2.64 Å. The Ti(8)-Si(1) bond length is 2.69 Å. The Ti(8)-Si(3) bond length is 2.56 Å. Both Ti(8)-Si(7) bond lengths are 2.79 Å. In the ninth Ti site, Ti(9) is bonded in a 5-coordinate geometry to one Al(1), one Al(3), one Si(2), and two equivalent Si(8) atoms. The Ti(9)-Al(1) bond length is 2.62 Å. The Ti(9)-Al(3) bond length is 2.62 Å. The Ti(9)-Si(2) bond length is 2.70 Å. Both Ti(9)-Si(8) bond lengths are 2.79 Å. In the tenth Ti site, Ti(10) is bonded in a 5-coordinate geometry to one Al(2), one Si(1), one Si(3), and two equivalent Si(9) atoms. The Ti(10)-Al(2) bond length is 2.63 Å. The Ti(10)-Si(1) bond length is 2.56 Å. The Ti(10)-Si(3) bond length is 2.69 Å. Both Ti(10)-Si(9) bond lengths are 2.80 Å. In the eleventh Ti site, Ti(11) is bonded in a 5-coordinate geometry to two equivalent Al(2), one Si(5), one Si(6), and one Si(9) atom. Both Ti(11)-Al(2) bond lengths are 2.81 Å. The Ti(11)-Si(5) bond length is 2.73 Å. The Ti(11)-Si(6) bond length is 2.59 Å. The Ti(11)-Si(9) bond length is 2.56 Å. In the twelfth Ti site, Ti(12) is bonded in a 5-coordinate geometry to two equivalent Al(1), one Si(4), one Si(7), and one Si(8) atom. Both Ti(12)-Al(1) bond lengths are 2.82 Å. The Ti(12)-Si(4) bond length is 2.73 Å. The Ti(12)-Si(7) bond length is 2.56 Å. The Ti(12)-Si(8) bond length is 2.57 Å. In the thirteenth Ti site, Ti(13) is bonded in a 5-coordinate geometry to two equivalent Al(3), one Si(4), one Si(6), and one Si(8) atom. Both Ti(13)-Al(3) bond lengths are 2.83 Å. The Ti(13)-Si(4) bond length is 2.59 Å. The Ti(13)-Si(6) bond length is 2.72 Å. The Ti(13)-Si(8) bond length is 2.57 Å. In the fourteenth Ti site, Ti(14) is bonded in a 5-coordinate geometry to one Si(5), one Si(7), one Si(9), and two equivalent Si(1) atoms. The Ti(14)-Si(5) bond length is 2.59 Å. The Ti(14)-Si(7) bond length is 2.70 Å. The Ti(14)-Si(9) bond length is 2.60 Å. Both Ti(14)-Si(1) bond lengths are 2.80 Å. In the fifteenth Ti site, Ti(15) is bonded in a 5-coordinate geometry to one Si(5), one Si(6), one Si(8), and two equivalent Si(2) atoms. The Ti(15)-Si(5) bond length is 2.61 Å. The Ti(15)-Si(6) bond length is 2.63 Å. The Ti(15)-Si(8) bond length is 2.72 Å. Both Ti(15)-Si(2) bond lengths are 2.80 Å. In the sixteenth Ti site, Ti(16) is bonded in a 5-coordinate geometry to one Si(4), one Si(7), one Si(9), and two equivalent Si(3) atoms. The Ti(16)-Si(4) bond length is 2.61 Å. The Ti(16)-Si(7) bond length is 2.60 Å. The Ti(16)-Si(9) bond length is 2.69 Å. Both Ti(16)-Si(3) bond lengths are 2.80 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to one Ti(6), one Ti(8), one Ti(9), two equivalent Ti(12), two equivalent Ti(2), and two equivalent Ti(3) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(5), one Ti(7), two equivalent Ti(1), two equivalent Ti(11), and two equivalent Ti(4) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to one Ti(6), one Ti(7), one Ti(9), two equivalent Ti(1), two equivalent Ti(13), and two equivalent Ti(3) atoms. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(5), one Ti(8), two equivalent Ti(14), two equivalent Ti(2), and two equivalent Ti(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Ti(5), one Ti(7), one Ti(9), two equivalent Ti(1), two equivalent Ti(15), and two equivalent Ti(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Ti(10), one Ti(6), one Ti(8), two equivalent Ti(16), two equivalent Ti(2), and two equivalent Ti(4) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(13), one Ti(16), two equivalent Ti(2), two equivalent Ti(3), and two equivalent Ti(6) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(14), one Ti(15), two equivalent Ti(1), two equivalent Ti(4), and two equivalent Ti(5) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(13), one Ti(15), two equivalent Ti(1), two equivalent Ti(3), and two equivalent Ti(7) atoms. In the seventh Si site, Si(7) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(14), one Ti(16), two equivalent Ti(2), two equivalent Ti(4), and two equivalent Ti(8) atoms. In the eighth Si site, Si(8) is bonded in a 9-coordinate geometry to one Ti(12), one Ti(13), one Ti(15), two equivalent Ti(1), two equivalent Ti(3), and two equivalent Ti(9) atoms. In the ninth Si site, Si(9) is bonded in a 9-coordinate geometry to one Ti(11), one Ti(14), one Ti(16), two equivalent Ti(10), two equivalent Ti(2), and two equivalent Ti(4) atoms.