Ca2C24P3H21O23 crystallizes in the orthorhombic Pca2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(10), one O(17), one O(18), one O(2), one O(23), and one O(6) atom to form CaO7 pentagonal bipyramids that share  a cornercorner with one P(2)CO3 tetrahedra, corners with two equivalent P(1)CO3 tetrahedra, edges with two equivalent Ca(2)O7 pentagonal bipyramids, and  an edgeedge with one P(3)CO3 tetrahedra. The Ca(1)-O(1) bond length is 2.30 Å. The Ca(1)-O(10) bond length is 2.43 Å. The Ca(1)-O(17) bond length is 2.46 Å. The Ca(1)-O(18) bond length is 2.51 Å. The Ca(1)-O(2) bond length is 2.31 Å. The Ca(1)-O(23) bond length is 2.41 Å. The Ca(1)-O(6) bond length is 2.37 Å. In the second Ca site, Ca(2) is bonded to one O(1), one O(13), one O(17), one O(18), one O(2), one O(7), and one O(9) atom to form CaO7 pentagonal bipyramids that share corners with two equivalent P(3)CO3 tetrahedra, edges with two equivalent Ca(1)O7 pentagonal bipyramids, and  an edgeedge with one P(1)CO3 tetrahedra. The Ca(2)-O(1) bond length is 2.60 Å. The Ca(2)-O(13) bond length is 2.42 Å. The Ca(2)-O(17) bond length is 2.30 Å. The Ca(2)-O(18) bond length is 2.31 Å. The Ca(2)-O(2) bond length is 2.49 Å. The Ca(2)-O(7) bond length is 2.34 Å. The Ca(2)-O(9) bond length is 2.38 Å. There are twenty-four inequivalent C sites. In the first C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(8), and one O(9) atom. The C(7)-C(6) bond length is 1.48 Å. The C(7)-O(8) bond length is 1.32 Å. The C(7)-O(9) bond length is 1.24 Å. In the second C site, C(8) is bonded in a distorted single-bond geometry to one C(1), one C(6), and one H(15) atom. The C(8)-C(1) bond length is 1.40 Å. The C(8)-C(6) bond length is 1.40 Å. The C(8)-H(15) bond length is 1.09 Å. In the third C site, C(9) is bonded in a trigonal planar geometry to one C(10), one C(16), and one P(2) atom. The C(9)-C(10) bond length is 1.40 Å. The C(9)-C(16) bond length is 1.40 Å. The C(9)-P(2) bond length is 1.80 Å. In the fourth C site, C(10) is bonded in a distorted single-bond geometry to one C(11), one C(9), and one H(16) atom. The C(10)-C(11) bond length is 1.40 Å. The C(10)-H(16) bond length is 1.09 Å. In the fifth C site, C(11) is bonded in a trigonal planar geometry to one C(10), one C(12), and one C(13) atom. The C(11)-C(12) bond length is 1.51 Å. The C(11)-C(13) bond length is 1.40 Å. In the sixth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(13), and one O(14) atom. The C(12)-O(13) bond length is 1.29 Å. The C(12)-O(14) bond length is 1.25 Å. In the seventh C site, C(13) is bonded in a distorted single-bond geometry to one C(11), one C(14), and one H(17) atom. The C(13)-C(14) bond length is 1.40 Å. The C(13)-H(17) bond length is 1.09 Å. In the eighth C site, C(14) is bonded in a trigonal planar geometry to one C(13), one C(15), and one C(16) atom. The C(14)-C(15) bond length is 1.49 Å. The C(14)-C(16) bond length is 1.40 Å. In the ninth C site, C(15) is bonded in a distorted bent 120 degrees geometry to one C(14), one O(15), and one O(16) atom. The C(15)-O(15) bond length is 1.36 Å. The C(15)-O(16) bond length is 1.22 Å. In the tenth C site, C(16) is bonded in a distorted single-bond geometry to one C(14), one C(9), and one H(18) atom. The C(16)-H(18) bond length is 1.09 Å. In the eleventh C site, C(17) is bonded in a trigonal planar geometry to one C(18), one C(24), and one P(3) atom. The C(17)-C(18) bond length is 1.40 Å. The C(17)-C(24) bond length is 1.40 Å. The C(17)-P(3) bond length is 1.80 Å. In the twelfth C site, C(18) is bonded in a distorted single-bond geometry to one C(17), one C(19), and one H(19) atom. The C(18)-C(19) bond length is 1.40 Å. The C(18)-H(19) bond length is 1.09 Å. In the thirteenth C site, C(19) is bonded in a trigonal planar geometry to one C(18), one C(20), and one C(21) atom. The C(19)-C(20) bond length is 1.48 Å. The C(19)-C(21) bond length is 1.39 Å. In the fourteenth C site, C(20) is bonded in a distorted bent 120 degrees geometry to one C(19), one O(20), and one O(21) atom. The C(20)-O(20) bond length is 1.32 Å. The C(20)-O(21) bond length is 1.25 Å. In the fifteenth C site, C(21) is bonded in a distorted single-bond geometry to one C(19), one C(22), and one H(20) atom. The C(21)-C(22) bond length is 1.40 Å. The C(21)-H(20) bond length is 1.09 Å. In the sixteenth C site, C(22) is bonded in a trigonal planar geometry to one C(21), one C(23), and one C(24) atom. The C(22)-C(23) bond length is 1.48 Å. The C(22)-C(24) bond length is 1.40 Å. In the seventeenth C site, C(23) is bonded in a distorted bent 120 degrees geometry to one C(22), one O(22), and one O(23) atom. The C(23)-O(22) bond length is 1.33 Å. The C(23)-O(23) bond length is 1.24 Å. In the eighteenth C site, C(24) is bonded in a distorted single-bond geometry to one C(17), one C(22), and one H(21) atom. The C(24)-H(21) bond length is 1.09 Å. In the nineteenth C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(8), and one P(1) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-P(1) bond length is 1.81 Å. In the twentieth C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(13) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(13) bond length is 1.09 Å. In the twenty-first C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(5) atom. The C(3)-C(4) bond length is 1.48 Å. The C(3)-C(5) bond length is 1.40 Å. In the twenty-second C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(4), and one O(5) atom. The C(4)-O(4) bond length is 1.32 Å. The C(4)-O(5) bond length is 1.25 Å. In the twenty-third C site, C(5) is bonded in a distorted single-bond geometry to one C(3), one C(6), and one H(14) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(14) bond length is 1.09 Å. In the twenty-fourth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(8) atom. There are three inequivalent P sites. In the first P site, P(1) is bonded to one C(1), one O(1), one O(2), and one O(3) atom to form PCO3 tetrahedra that share corners with two equivalent Ca(1)O7 pentagonal bipyramids and  an edgeedge with one Ca(2)O7 pentagonal bipyramid. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.60 Å. In the second P site, P(2) is bonded to one C(9), one O(10), one O(11), and one O(12) atom to form distorted PCO3 tetrahedra that share  a cornercorner with one Ca(1)O7 pentagonal bipyramid. The P(2)-O(10) bond length is 1.52 Å. The P(2)-O(11) bond length is 1.52 Å. The P(2)-O(12) bond length is 1.63 Å. In the third P site, P(3) is bonded to one C(17), one O(17), one O(18), and one O(19) atom to form PCO3 tetrahedra that share corners with two equivalent Ca(2)O7 pentagonal bipyramids and  an edgeedge with one Ca(1)O7 pentagonal bipyramid. The P(3)-O(17) bond length is 1.53 Å. The P(3)-O(18) bond length is 1.53 Å. The P(3)-O(19) bond length is 1.58 Å. There are twenty-one inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.98 Å. In the second H site, H(2) is bonded in a linear geometry to one O(21) and one O(4) atom. The H(2)-O(21) bond length is 1.57 Å. The H(2)-O(4) bond length is 1.03 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(6) atom. The H(3)-O(6) bond length is 0.97 Å. In the fourth H site, H(4) is bonded in a linear geometry to one O(14) and one O(6) atom. The H(4)-O(14) bond length is 1.62 Å. The H(4)-O(6) bond length is 1.01 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(11) and one O(7) atom. The H(5)-O(11) bond length is 1.75 Å. The H(5)-O(7) bond length is 0.99 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(7) atom. The H(6)-O(7) bond length is 0.98 Å. In the seventh H site, H(7) is bonded in a linear geometry to one O(13) and one O(8) atom. The H(7)-O(13) bond length is 1.50 Å. The H(7)-O(8) bond length is 1.05 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(12) atom. The H(8)-O(12) bond length is 0.98 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(15) atom. The H(9)-O(15) bond length is 0.98 Å. In the tenth H site, H(10) is bonded in a distorted linear geometry to one O(11) and one O(19) atom. The H(10)-O(11) bond length is 1.59 Å. The H(10)-O(19) bond length is 1.02 Å. In the eleventh H site, H(11) is bonded in a linear geometry to one O(20) and one O(5) atom. The H(11)-O(20) bond length is 1.04 Å. The H(11)-O(5) bond length is 1.49 Å. In the twelfth H site, H(12) is bonded in a linear geometry to one O(10) and one O(22) atom. The H(12)-O(10) bond length is 1.57 Å. The H(12)-O(22) bond length is 1.03 Å. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one C(2) atom. In the fourteenth H site, H(14) is bonded in a single-bond geometry to one C(5) atom. In the fifteenth H site, H(15) is bonded in a single-bond geometry to one C(8) atom. In the sixteenth H site, H(16) is bonded in a single-bond geometry to one C(10) atom. In the seventeenth H site, H(17) is bonded in a single-bond geometry to one C(13) atom. In the eighteenth H site, H(18) is bonded in a single-bond geometry to one C(16) atom. In the nineteenth H site, H(19) is bonded in a single-bond geometry to one C(18) atom. In the twentieth H site, H(20) is bonded in a single-bond geometry to one C(21) atom. In the twenty-first H site, H(21) is bonded in a single-bond geometry to one C(24) atom. There are twenty-three inequivalent O sites. In the first O site, O(15) is bonded in a water-like geometry to one C(15) and one H(9) atom. In the second O site, O(16) is bonded in a single-bond geometry to one C(15) atom. In the third O site, O(17) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(3) atom. In the fourth O site, O(18) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(3) atom. In the fifth O site, O(19) is bonded in a water-like geometry to one P(3) and one H(10) atom. In the sixth O site, O(20) is bonded in a water-like geometry to one C(20) and one H(11) atom. In the seventh O site, O(21) is bonded in a bent 120 degrees geometry to one C(20) and one H(2) atom. In the eighth O site, O(22) is bonded in a water-like geometry to one C(23) and one H(12) atom. In the ninth O site, O(23) is bonded in a distorted single-bond geometry to one Ca(1) and one C(23) atom. In the tenth O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the eleventh O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the twelfth O site, O(3) is bonded in a bent 120 degrees geometry to one P(1) and one H(1) atom. In the thirteenth O site, O(4) is bonded in a water-like geometry to one C(4) and one H(2) atom. In the fourteenth O site, O(5) is bonded in a bent 120 degrees geometry to one C(4) and one H(11) atom. In the fifteenth O site, O(6) is bonded in a 3-coordinate geometry to one Ca(1), one H(3), and one H(4) atom. In the sixteenth O site, O(7) is bonded in a distorted trigonal planar geometry to one Ca(2), one H(5), and one H(6) atom. In the seventeenth O site, O(13) is bonded in a 3-coordinate geometry to one Ca(2), one C(12), and one H(7) atom. In the eighteenth O site, O(8) is bonded in a water-like geometry to one C(7) and one H(7) atom. In the nineteenth O site, O(9) is bonded in a 2-coordinate geometry to one Ca(2) and one C(7) atom. In the twentieth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one P(2), and one H(12) atom. In the twenty-first O site, O(11) is bonded in a 3-coordinate geometry to one P(2), one H(10), and one H(5) atom. In the twenty-second O site, O(12) is bonded in a distorted bent 120 degrees geometry to one P(2) and one H(8) atom. In the twenty-third O site, O(14) is bonded in a bent 120 degrees geometry to one C(12) and one H(4) atom. Linkers: 8 [O]P(=O)(O)c1cc(C(=O)O)cc(C(=O)O)c1 ,4 [O]C(=O)c1cc(C(=O)O)cc(P([O])(=O)O)c1. Metal clusters: 8 [Ca]. The MOF has largest included sphere 3.84 A, density 1.60 g/cm3, surface area 4013.38 m2/g, accessible volume 0.23 cm3/g