KLaS2O9 crystallizes in the trigonal P3_121 space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. La(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. S(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one La(1), and one S(1) atom. In the second O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one La(1), and one S(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one La(1), and one S(1) atom. In the fourth O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one La(1), and one S(1) atom. In the fifth O site, O(4) is bonded in a single-bond geometry to one La(1) atom.
KLaS2O9 crystallizes in the trigonal P3_121 space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Both K(1)-O(1) bond lengths are 2.96 Å. Both K(1)-O(2) bond lengths are 2.60 Å. Both K(1)-O(3) bond lengths are 2.84 Å. Both K(1)-O(5) bond lengths are 2.76 Å. La(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. The La(1)-O(4) bond length is 2.58 Å. Both La(1)-O(1) bond lengths are 2.54 Å. Both La(1)-O(2) bond lengths are 2.52 Å. Both La(1)-O(3) bond lengths are 2.62 Å. Both La(1)-O(5) bond lengths are 2.66 Å. S(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(5) atom. The S(1)-O(1) bond length is 1.48 Å. The S(1)-O(2) bond length is 1.50 Å. The S(1)-O(3) bond length is 1.49 Å. The S(1)-O(5) bond length is 1.50 Å. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one La(1), and one S(1) atom. In the second O site, O(1) is bonded in a 1-coordinate geometry to one K(1), one La(1), and one S(1) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one La(1), and one S(1) atom. In the fourth O site, O(3) is bonded in a distorted single-bond geometry to one K(1), one La(1), and one S(1) atom. In the fifth O site, O(4) is bonded in a single-bond geometry to one La(1) atom.