K2Ce(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(5), one O(6), two equivalent O(1), and two equivalent O(8) 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(5), one O(7), two equivalent O(4), and two equivalent O(6) atoms. Ce(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(2), one Ce(1), and one P(1) atom. In the second O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one K(2), one Ce(1), and one P(2) atom. In the third O site, O(6) is bonded in a 1-coordinate geometry to one K(1), two equivalent K(2), one Ce(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a 3-coordinate geometry to one K(2), one Ce(1), and one P(2) atom. In the fifth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent K(1), one Ce(1), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), one Ce(1), and one P(1) atom. In the seventh O site, O(2) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ce(1), and one P(1) atom. In the eighth O site, O(3) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ce(1), and one P(1) atom.
K2Ce(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(5), one O(6), two equivalent O(1), and two equivalent O(8) atoms. The K(1)-O(2) bond length is 2.85 Å. The K(1)-O(3) bond length is 2.90 Å. The K(1)-O(5) bond length is 2.63 Å. The K(1)-O(6) bond length is 2.90 Å. There is one shorter (2.75 Å) and one longer (2.93 Å) K(1)-O(1) bond length. There is one shorter (2.66 Å) and one longer (2.73 Å) K(1)-O(8) bond length. 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(5), one O(7), two equivalent O(4), and two equivalent O(6) atoms. The K(2)-O(1) bond length is 2.65 Å. The K(2)-O(2) bond length is 3.11 Å. The K(2)-O(3) bond length is 2.92 Å. The K(2)-O(5) bond length is 2.74 Å. The K(2)-O(7) bond length is 2.74 Å. There is one shorter (2.65 Å) and one longer (2.93 Å) K(2)-O(4) bond length. Both K(2)-O(6) bond lengths are 3.03 Å. Ce(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Ce(1)-O(1) bond length is 2.41 Å. The Ce(1)-O(2) bond length is 2.32 Å. The Ce(1)-O(3) bond length is 2.34 Å. The Ce(1)-O(4) bond length is 2.48 Å. The Ce(1)-O(5) bond length is 2.38 Å. The Ce(1)-O(6) bond length is 2.38 Å. The Ce(1)-O(7) bond length is 2.33 Å. The Ce(1)-O(8) bond length is 2.45 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.53 Å. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(5), one O(6), one O(7), and one O(8) atom. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(6) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.54 Å. The P(2)-O(8) bond length is 1.54 Å. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(2), one Ce(1), and one P(1) atom. In the second O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one K(2), one Ce(1), and one P(2) atom. In the third O site, O(6) is bonded in a 1-coordinate geometry to one K(1), two equivalent K(2), one Ce(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a 3-coordinate geometry to one K(2), one Ce(1), and one P(2) atom. In the fifth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent K(1), one Ce(1), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one K(2), two equivalent K(1), one Ce(1), and one P(1) atom. In the seventh O site, O(2) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ce(1), and one P(1) atom. In the eighth O site, O(3) is bonded in a 1-coordinate geometry to one K(1), one K(2), one Ce(1), and one P(1) atom.