Ca2P3H17(C8O7)3 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(15), one O(16), one O(2), one O(21), and one O(8) atom to form CaO6 pentagonal pyramids that share  a cornercorner with one P(2)CO3 tetrahedra, corners with two equivalent P(1)CO3 tetrahedra, edges with two equivalent Ca(2)O6 pentagonal pyramids, and  an edgeedge with one P(3)CO3 tetrahedra. The Ca(1)-O(1) bond length is 2.31 Å. The Ca(1)-O(15) bond length is 2.47 Å. The Ca(1)-O(16) bond length is 2.51 Å. The Ca(1)-O(2) bond length is 2.30 Å. The Ca(1)-O(21) bond length is 2.43 Å. The Ca(1)-O(8) bond length is 2.39 Å. In the second Ca site, Ca(2) is bonded to one O(1), one O(11), one O(15), one O(16), one O(2), and one O(7) atom to form CaO6 pentagonal pyramids that share corners with two equivalent P(3)CO3 tetrahedra, edges with two equivalent Ca(1)O6 pentagonal pyramids, and  an edgeedge with one P(1)CO3 tetrahedra. The Ca(2)-O(1) bond length is 2.50 Å. The Ca(2)-O(11) bond length is 2.38 Å. The Ca(2)-O(15) bond length is 2.33 Å. The Ca(2)-O(16) bond length is 2.29 Å. The Ca(2)-O(2) bond length is 2.52 Å. The Ca(2)-O(7) bond length is 2.41 Å. There are twenty-four inequivalent C sites. In the first 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)-C(8) bond length is 1.39 Å. The C(1)-P(1) bond length is 1.81 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(9) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(9) bond length is 0.95 Å. In the third 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 1.49 Å. The C(3)-C(5) bond length is 1.40 Å. In the fourth 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 1.29 Å. The C(4)-O(5) bond length is 1.27 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(3), one C(6), and one H(10) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(10) bond length is 0.95 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(8) atom. The C(6)-C(7) bond length is 1.48 Å. The C(6)-C(8) bond length is 1.41 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(6), and one O(7) atom. The C(7)-O(6) bond length is 1.33 Å. The C(7)-O(7) bond length is 1.23 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(1), one C(6), and one H(11) atom. The C(8)-H(11) bond length is 0.95 Å. In the ninth 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 1.39 Å. The C(9)-C(16) bond length is 1.39 Å. The C(9)-P(2) bond length is 1.81 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(11), one C(9), and one H(12) atom. The C(10)-C(11) bond length is 1.37 Å. The C(10)-H(12) bond length is 0.95 Å. In the eleventh 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 1.55 Å. The C(11)-C(13) bond length is 1.38 Å. In the twelfth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(11), one O(11), and one O(12) atom. The C(12)-O(11) bond length is 1.31 Å. The C(12)-O(12) bond length is 1.21 Å. In the thirteenth C site, C(13) is bonded in a distorted single-bond geometry to one C(11), one C(14), and one H(13) atom. The C(13)-C(14) bond length is 1.45 Å. The C(13)-H(13) bond length is 0.95 Å. In the fourteenth 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 1.50 Å. The C(14)-C(16) bond length is 1.36 Å. In the fifteenth C site, C(15) is bonded in a distorted bent 120 degrees geometry to one C(14), one O(13), and one O(14) atom. The C(15)-O(13) bond length is 1.33 Å. The C(15)-O(14) bond length is 1.23 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(14), one C(9), and one H(14) atom. The C(16)-H(14) bond length is 0.95 Å. In the seventeenth 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 1.39 Å. The C(17)-C(24) bond length is 1.39 Å. The C(17)-P(3) bond length is 1.79 Å. In the eighteenth C site, C(18) is bonded in a distorted single-bond geometry to one C(17), one C(19), and one H(15) atom. The C(18)-C(19) bond length is 1.39 Å. The C(18)-H(15) bond length is 0.95 Å. In the nineteenth 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 1.50 Å. The C(19)-C(21) bond length is 1.39 Å. In the twentieth C site, C(20) is bonded in a distorted bent 120 degrees geometry to one C(19), one O(18), and one O(19) atom. The C(20)-O(18) bond length is 1.31 Å. The C(20)-O(19) bond length is 1.23 Å. In the twenty-first C site, C(21) is bonded in a distorted single-bond geometry to one C(19), one C(22), and one H(16) atom. The C(21)-C(22) bond length is 1.40 Å. The C(21)-H(16) bond length is 0.95 Å. In the twenty-second 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 1.47 Å. The C(22)-C(24) bond length is 1.40 Å. In the twenty-third C site, C(23) is bonded in a distorted bent 120 degrees geometry to one C(22), one O(20), and one O(21) atom. The C(23)-O(20) bond length is 1.35 Å. The C(23)-O(21) bond length is 1.21 Å. In the twenty-fourth C site, C(24) is bonded in a distorted single-bond geometry to one C(17), one C(22), and one H(17) atom. The C(24)-H(17) bond length is 0.95 Å. 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 distorted PCO3 tetrahedra that share corners with two equivalent Ca(1)O6 pentagonal pyramids and  an edgeedge with one Ca(2)O6 pentagonal pyramid. The P(1)-O(1) bond length is 1.50 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.57 Å. In the second P site, P(2) is bonded to one C(9), one O(10), one O(8), and one O(9) atom to form distorted PCO3 tetrahedra that share  a cornercorner with one Ca(1)O6 pentagonal pyramid. The P(2)-O(10) bond length is 1.56 Å. The P(2)-O(8) bond length is 1.52 Å. The P(2)-O(9) bond length is 1.53 Å. In the third P site, P(3) is bonded to one C(17), one O(15), one O(16), and one O(17) atom to form distorted PCO3 tetrahedra that share corners with two equivalent Ca(2)O6 pentagonal pyramids and  an edgeedge with one Ca(1)O6 pentagonal pyramid. The P(3)-O(15) bond length is 1.49 Å. The P(3)-O(16) bond length is 1.53 Å. The P(3)-O(17) bond length is 1.57 Å. There are seventeen 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 0.84 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) atom. The H(2)-O(4) bond length is 0.84 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(11) and one O(6) atom. The H(3)-O(11) bond length is 1.73 Å. The H(3)-O(6) bond length is 0.84 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(10) atom. The H(4)-O(10) bond length is 0.84 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(13) atom. The H(5)-O(13) bond length is 0.84 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(17) atom. The H(6)-O(17) bond length is 0.84 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(18) atom. The H(7)-O(18) bond length is 0.84 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(20) atom. The H(8)-O(20) bond length is 0.84 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(2) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(5) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(8) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one C(10) atom. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one C(13) atom. In the fourteenth H site, H(14) is bonded in a single-bond geometry to one C(16) atom. In the fifteenth H site, H(15) is bonded in a single-bond geometry to one C(18) atom. In the sixteenth H site, H(16) is bonded in a single-bond geometry to one C(21) atom. In the seventeenth H site, H(17) is bonded in a single-bond geometry to one C(24) atom. There are twenty-one inequivalent O sites. In the first 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 second 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 third O site, O(3) is bonded in a water-like geometry to one P(1) and one H(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one C(4) and one H(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one C(4) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one C(7) and one H(3) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ca(2) and one C(7) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Ca(1) and one P(2) atom. In the ninth O site, O(9) is bonded in a single-bond geometry to one P(2) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one P(2) and one H(4) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ca(2), one C(12), and one H(3) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one C(12) atom. In the thirteenth O site, O(13) is bonded in a water-like geometry to one C(15) and one H(5) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one C(15) atom. In the fifteenth O site, O(15) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(3) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(3) atom. In the seventeenth O site, O(17) is bonded in a water-like geometry to one P(3) and one H(6) atom. In the eighteenth O site, O(18) is bonded in a water-like geometry to one C(20) and one H(7) atom. In the nineteenth O site, O(19) is bonded in a single-bond geometry to one C(20) atom. In the twentieth O site, O(20) is bonded in a water-like geometry to one C(23) and one H(8) atom. In the twenty-first O site, O(21) is bonded in a distorted single-bond geometry to one Ca(1) and one C(23) atom. Linkers: 4 [O]C(=O)c1cc(C(=O)O)cc(P([O])(=O)O)c1 ,8 [O]P(=O)(O)c1cc(C(=O)O)cc(C(=O)O)c1. Metal clusters: 8 [Ca]. The MOF has largest included sphere 4.63 A, density 1.49 g/cm3, surface area 4026.23 m2/g, accessible volume 0.26 cm3/g