K3Ce(AsO4)2 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 1-coordinate geometry to one O(4) and one O(6) atom. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. In the third K site, K(3) is bonded in a 9-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and three equivalent O(4) atoms. Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(5) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(3), one O(6), and two equivalent O(2) atoms. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(1), one O(4), and two equivalent O(5) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(2), one Ce(1), and one As(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2), one K(3), one Ce(1), and one As(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one K(3), one Ce(1), and one As(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(1), one K(2), three equivalent K(3), and one As(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one K(3), two equivalent K(2), one Ce(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Ce(1), and one As(1) atom.
K3Ce(AsO4)2 crystallizes in the monoclinic P2_1/m space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 1-coordinate geometry to one O(4) and one O(6) atom. The K(1)-O(4) bond length is 3.14 Å. The K(1)-O(6) bond length is 2.62 Å. In the second K site, K(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. The K(2)-O(4) bond length is 2.65 Å. Both K(2)-O(1) bond lengths are 2.99 Å. Both K(2)-O(2) bond lengths are 2.93 Å. There are two shorter (2.94 Å) and two longer (3.21 Å) K(2)-O(5) bond lengths. In the third K site, K(3) is bonded in a 9-coordinate geometry to one O(1), one O(3), two equivalent O(2), two equivalent O(5), and three equivalent O(4) atoms. The K(3)-O(1) bond length is 2.74 Å. The K(3)-O(3) bond length is 2.68 Å. Both K(3)-O(2) bond lengths are 2.94 Å. Both K(3)-O(5) bond lengths are 3.11 Å. There is one shorter (3.02 Å) and two longer (3.14 Å) K(3)-O(4) bond lengths. Ce(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), and two equivalent O(5) atoms. The Ce(1)-O(1) bond length is 2.51 Å. The Ce(1)-O(3) bond length is 2.70 Å. The Ce(1)-O(6) bond length is 2.57 Å. Both Ce(1)-O(2) bond lengths are 2.48 Å. Both Ce(1)-O(5) bond lengths are 2.35 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a tetrahedral geometry to one O(3), one O(6), and two equivalent O(2) atoms. The As(1)-O(3) bond length is 1.72 Å. The As(1)-O(6) bond length is 1.72 Å. Both As(1)-O(2) bond lengths are 1.73 Å. In the second As site, As(2) is bonded in a tetrahedral geometry to one O(1), one O(4), and two equivalent O(5) atoms. The As(2)-O(1) bond length is 1.72 Å. The As(2)-O(4) bond length is 1.71 Å. Both As(2)-O(5) bond lengths are 1.73 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(2), one Ce(1), and one As(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(2), one K(3), one Ce(1), and one As(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one K(3), one Ce(1), and one As(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(1), one K(2), three equivalent K(3), and one As(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one K(3), two equivalent K(2), one Ce(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one Ce(1), and one As(1) atom.