KAlSiO4 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and three equivalent O(7) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and three equivalent O(8) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra and corners with three equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to three equivalent K(1), one Al(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to three equivalent K(2), one Al(2), and one Si(2) atom.
KAlSiO4 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and three equivalent O(7) atoms. The K(1)-O(1) bond length is 3.03 Å. The K(1)-O(2) bond length is 2.92 Å. The K(1)-O(3) bond length is 3.01 Å. The K(1)-O(4) bond length is 3.08 Å. The K(1)-O(5) bond length is 2.95 Å. The K(1)-O(6) bond length is 3.09 Å. There are a spread of K(1)-O(7) bond distances ranging from 2.93-3.10 Å. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and three equivalent O(8) atoms. The K(2)-O(1) bond length is 2.99 Å. The K(2)-O(2) bond length is 3.10 Å. The K(2)-O(3) bond length is 3.04 Å. The K(2)-O(4) bond length is 2.94 Å. The K(2)-O(5) bond length is 3.07 Å. The K(2)-O(6) bond length is 2.95 Å. There are a spread of K(2)-O(8) bond distances ranging from 2.95-3.12 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. The Al(1)-O(4) bond length is 1.76 Å. The Al(1)-O(5) bond length is 1.76 Å. The Al(1)-O(6) bond length is 1.76 Å. The Al(1)-O(7) bond length is 1.75 Å. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(2)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. The Al(2)-O(1) bond length is 1.76 Å. The Al(2)-O(2) bond length is 1.76 Å. The Al(2)-O(3) bond length is 1.76 Å. The Al(2)-O(8) bond length is 1.75 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra and corners with three equivalent Al(2)O4 tetrahedra. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.64 Å. The Si(1)-O(7) bond length is 1.63 Å. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. The Si(2)-O(4) bond length is 1.64 Å. The Si(2)-O(5) bond length is 1.64 Å. The Si(2)-O(6) bond length is 1.64 Å. The Si(2)-O(8) bond length is 1.64 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(2), one Al(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted linear geometry to three equivalent K(1), one Al(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to three equivalent K(2), one Al(2), and one Si(2) atom.