BaC2P2H6O7 crystallizes in the triclinic P-1 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(10), one O(15), one O(19), one O(20), one O(21), one O(3), one O(4), one O(7), and two equivalent O(13) atoms. The Ba(1)-O(10) bond length is 2.74 Å. The Ba(1)-O(15) bond length is 3.05 Å. The Ba(1)-O(19) bond length is 2.87 Å. The Ba(1)-O(20) bond length is 2.88 Å. The Ba(1)-O(21) bond length is 2.83 Å. The Ba(1)-O(3) bond length is 2.79 Å. The Ba(1)-O(4) bond length is 2.78 Å. The Ba(1)-O(7) bond length is 3.05 Å. There is one shorter (2.79 Å) and one longer (2.88 Å) Ba(1)-O(13) bond length. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(14), one O(2), one O(3), and one O(4) atom. The Ba(2)-O(1) bond length is 2.88 Å. The Ba(2)-O(10) bond length is 2.76 Å. The Ba(2)-O(11) bond length is 2.70 Å. The Ba(2)-O(12) bond length is 2.94 Å. The Ba(2)-O(13) bond length is 2.74 Å. The Ba(2)-O(14) bond length is 3.06 Å. The Ba(2)-O(2) bond length is 2.70 Å. The Ba(2)-O(3) bond length is 3.17 Å. The Ba(2)-O(4) bond length is 2.65 Å. In the third Ba site, Ba(3) is bonded in a 9-coordinate geometry to one O(10), one O(11), one O(15), one O(17), one O(2), one O(3), one O(6), and two equivalent O(7) atoms. The Ba(3)-O(10) bond length is 3.26 Å. The Ba(3)-O(11) bond length is 2.93 Å. The Ba(3)-O(15) bond length is 2.60 Å. The Ba(3)-O(17) bond length is 2.74 Å. The Ba(3)-O(2) bond length is 3.01 Å. The Ba(3)-O(3) bond length is 3.02 Å. The Ba(3)-O(6) bond length is 2.75 Å. There is one shorter (2.71 Å) and one longer (3.27 Å) Ba(3)-O(7) bond length. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted tetrahedral geometry to one C(4), one P(3), one P(4), and one O(21) atom. The C(1)-C(4) bond length is 1.52 Å. The C(1)-P(3) bond length is 1.86 Å. The C(1)-P(4) bond length is 1.86 Å. The C(1)-O(21) bond length is 1.46 Å. In the second C site, C(2) is bonded in a distorted tetrahedral geometry to one C(5), one P(1), one P(6), and one O(19) atom. The C(2)-C(5) bond length is 1.53 Å. The C(2)-P(1) bond length is 1.87 Å. The C(2)-P(6) bond length is 1.85 Å. The C(2)-O(19) bond length is 1.43 Å. In the third C site, C(3) is bonded in a distorted tetrahedral geometry to one C(6), one P(2), one P(5), and one O(20) atom. The C(3)-C(6) bond length is 1.52 Å. The C(3)-P(2) bond length is 1.86 Å. The C(3)-P(5) bond length is 1.85 Å. The C(3)-O(20) bond length is 1.45 Å. In the fourth C site, C(4) is bonded in a trigonal non-coplanar geometry to one C(1), one H(10), one H(11), and one H(12) atom. The C(4)-H(10) bond length is 1.10 Å. The C(4)-H(11) bond length is 1.10 Å. The C(4)-H(12) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal non-coplanar geometry to one C(2), one H(13), one H(14), and one H(15) atom. The C(5)-H(13) bond length is 1.10 Å. The C(5)-H(14) bond length is 1.10 Å. The C(5)-H(15) bond length is 1.10 Å. In the sixth C site, C(6) is bonded in a trigonal non-coplanar geometry to one C(3), one H(16), one H(17), and one H(18) atom. The C(6)-H(16) bond length is 1.10 Å. The C(6)-H(17) bond length is 1.10 Å. The C(6)-H(18) bond length is 1.09 Å. There are six inequivalent P sites. In the first P site, P(1) is bonded to one C(2), one O(1), one O(2), and one O(3) atom to form corner-sharing PCO3 tetrahedra. The P(1)-O(1) bond length is 1.59 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.52 Å. In the second P site, P(2) is bonded to one C(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing PCO3 tetrahedra. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.60 Å. The P(2)-O(6) bond length is 1.53 Å. In the third P site, P(3) is bonded to one C(1), one O(7), one O(8), and one O(9) atom to form distorted corner-sharing PCO3 tetrahedra. The P(3)-O(7) bond length is 1.53 Å. The P(3)-O(8) bond length is 1.53 Å. The P(3)-O(9) bond length is 1.59 Å. In the fourth P site, P(4) is bonded to one C(1), one O(10), one O(11), and one O(12) atom to form corner-sharing PCO3 tetrahedra. The P(4)-O(10) bond length is 1.52 Å. The P(4)-O(11) bond length is 1.52 Å. The P(4)-O(12) bond length is 1.59 Å. In the fifth P site, P(5) is bonded to one C(3), one O(13), one O(14), and one O(15) atom to form corner-sharing PCO3 tetrahedra. The P(5)-O(13) bond length is 1.53 Å. The P(5)-O(14) bond length is 1.59 Å. The P(5)-O(15) bond length is 1.51 Å. In the sixth P site, P(6) is bonded to one C(2), one O(16), one O(17), and one O(18) atom to form distorted corner-sharing PCO3 tetrahedra. The P(6)-O(16) bond length is 1.60 Å. The P(6)-O(17) bond length is 1.52 Å. The P(6)-O(18) bond length is 1.53 Å. There are eighteen inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(1) and one O(8) atom. The H(1)-O(1) bond length is 1.03 Å. The H(1)-O(8) bond length is 1.56 Å. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(18) and one O(5) atom. The H(2)-O(18) bond length is 1.66 Å. The H(2)-O(5) bond length is 1.00 Å. In the third H site, H(3) is bonded in a linear geometry to one O(17) and one O(9) atom. The H(3)-O(17) bond length is 1.57 Å. The H(3)-O(9) bond length is 1.02 Å. In the fourth H site, H(4) is bonded in a linear geometry to one O(12) and one O(6) atom. The H(4)-O(12) bond length is 1.06 Å. The H(4)-O(6) bond length is 1.44 Å. In the fifth H site, H(5) is bonded in a linear geometry to one O(14) and one O(8) atom. The H(5)-O(14) bond length is 1.03 Å. The H(5)-O(8) bond length is 1.51 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(16) atom. The H(6)-O(16) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a distorted bent 150 degrees geometry to one O(18) and one O(19) atom. The H(7)-O(18) bond length is 1.62 Å. The H(7)-O(19) bond length is 1.00 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(18) and one O(20) atom. The H(8)-O(18) bond length is 1.75 Å. The H(8)-O(20) bond length is 0.99 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(21) atom. The H(9)-O(21) bond length is 0.98 Å. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(4) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(4) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one C(4) atom. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one C(5) 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(5) atom. In the sixteenth H site, H(16) is bonded in a single-bond geometry to one C(6) atom. In the seventeenth H site, H(17) is bonded in a single-bond geometry to one C(6) atom. In the eighteenth H site, H(18) is bonded in a single-bond geometry to one C(6) atom. There are twenty-one inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(2), one P(1), and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), one Ba(3), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one P(2) and one H(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ba(3), one P(2), and one H(4) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(3), and one P(3) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one P(3), one H(1), and one H(5) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one P(3) and one H(3) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), one Ba(3), and one P(4) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Ba(2), one Ba(3), and one P(4) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one Ba(2), one P(4), and one H(4) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(5) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one Ba(2), one P(5), and one H(5) atom. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(3), and one P(5) atom. In the sixteenth O site, O(16) is bonded in a water-like geometry to one P(6) and one H(6) atom. In the seventeenth O site, O(17) is bonded in a distorted trigonal planar geometry to one Ba(3), one P(6), and one H(3) atom. In the eighteenth O site, O(18) is bonded in a 4-coordinate geometry to one P(6), one H(2), one H(7), and one H(8) atom. In the nineteenth O site, O(19) is bonded in a distorted water-like geometry to one Ba(1), one C(2), and one H(7) atom. In the twentieth O site, O(20) is bonded in a distorted water-like geometry to one Ba(1), one C(3), and one H(8) atom. In the twenty-first O site, O(21) is bonded in a distorted water-like geometry to one Ba(1), one C(1), and one H(9) atom. Linkers: 6 CC(O)(P([O])(=O)O)P([O])(=O)O. Metal clusters: 6 [Ba]. The MOF has largest included sphere 3.38 A, density 2.77 g/cm3, surface area 2264.14 m2/g, accessible volume 0.08 cm3/g