K2PH4O5 crystallizes in the monoclinic Cc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one H(2), one H(4), one O(1), one O(2), one O(5), one O(7), one O(8), and one O(9) atom. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(7), one O(8), and one O(9) atom. In the third K site, K(3) is bonded in a 2-coordinate geometry to one O(1) and one O(4) atom. In the fourth K site, K(4) is bonded in a 10-coordinate geometry to one H(3), one H(5), one H(8), one O(1), one O(10), one O(2), one O(4), one O(5), 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 trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. In the second P site, P(2) is bonded in a trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) and one O(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one K(1) and one O(7) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one K(4), one O(3), and one O(8) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one K(1) and one O(8) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one K(4) and one O(9) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(9) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(10) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one K(4) and one O(10) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one K(4), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one P(1), one H(1), and one H(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one K(2), one K(3), one K(4), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one K(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one P(2) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one K(1), one K(2), one K(4), one H(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one K(1), one K(2), one K(4), one H(3), and one H(4) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one K(1), one K(2), one H(5), and one H(6) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one K(2), one K(4), one H(7), and one H(8) atom.
K2PH4O5 crystallizes in the monoclinic Cc space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one H(2), one H(4), one O(1), one O(2), one O(5), one O(7), one O(8), and one O(9) atom. The K(1)-H(2) bond length is 2.87 Å. The K(1)-H(4) bond length is 2.71 Å. The K(1)-O(1) bond length is 2.78 Å. The K(1)-O(2) bond length is 2.74 Å. The K(1)-O(5) bond length is 3.09 Å. The K(1)-O(7) bond length is 2.97 Å. The K(1)-O(8) bond length is 2.85 Å. The K(1)-O(9) bond length is 2.82 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(4), one O(7), one O(8), and one O(9) atom. The K(2)-O(1) bond length is 3.01 Å. The K(2)-O(10) bond length is 2.77 Å. The K(2)-O(2) bond length is 2.85 Å. The K(2)-O(4) bond length is 2.80 Å. The K(2)-O(7) bond length is 2.87 Å. The K(2)-O(8) bond length is 2.88 Å. The K(2)-O(9) bond length is 3.04 Å. In the third K site, K(3) is bonded in a 2-coordinate geometry to one O(1) and one O(4) atom. The K(3)-O(1) bond length is 2.73 Å. The K(3)-O(4) bond length is 2.67 Å. In the fourth K site, K(4) is bonded in a 10-coordinate geometry to one H(3), one H(5), one H(8), one O(1), one O(10), one O(2), one O(4), one O(5), one O(7), and one O(8) atom. The K(4)-H(3) bond length is 3.01 Å. The K(4)-H(5) bond length is 2.93 Å. The K(4)-H(8) bond length is 2.72 Å. The K(4)-O(1) bond length is 3.03 Å. The K(4)-O(10) bond length is 2.89 Å. The K(4)-O(2) bond length is 2.94 Å. The K(4)-O(4) bond length is 2.79 Å. The K(4)-O(5) bond length is 2.75 Å. The K(4)-O(7) bond length is 2.92 Å. The K(4)-O(8) bond length is 3.09 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.57 Å. In the second P site, P(2) is bonded in a trigonal non-coplanar geometry to one O(4), one O(5), and one O(6) atom. The P(2)-O(4) bond length is 1.53 Å. The P(2)-O(5) bond length is 1.55 Å. The P(2)-O(6) bond length is 1.58 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) and one O(7) atom. The H(1)-O(3) bond length is 1.72 Å. The H(1)-O(7) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one K(1) and one O(7) atom. The H(2)-O(7) bond length is 1.00 Å. In the third H site, H(3) is bonded in a distorted single-bond geometry to one K(4), one O(3), and one O(8) atom. The H(3)-O(3) bond length is 1.67 Å. The H(3)-O(8) bond length is 1.01 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one K(1) and one O(8) atom. The H(4)-O(8) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one K(4) and one O(9) atom. The H(5)-O(9) bond length is 1.00 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(9) atom. The H(6)-O(9) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(10) atom. The H(7)-O(10) bond length is 1.00 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one K(4) and one O(10) atom. The H(8)-O(10) bond length is 0.99 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(3), one K(4), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), one K(4), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one P(1), one H(1), and one H(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one K(2), one K(3), one K(4), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1), one K(4), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one P(2) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one K(1), one K(2), one K(4), one H(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one K(1), one K(2), one K(4), one H(3), and one H(4) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one K(1), one K(2), one H(5), and one H(6) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one K(2), one K(4), one H(7), and one H(8) atom.