Sm2W11C2AsP2H4O37 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a distorted pentagonal planar geometry to one O(12), one O(28), one O(29), one O(31), and one O(32) atom. The Sm(1)-O(12) bond length is 2.47 Å. The Sm(1)-O(28) bond length is 2.47 Å. The Sm(1)-O(29) bond length is 2.47 Å. The Sm(1)-O(31) bond length is 2.45 Å. The Sm(1)-O(32) bond length is 2.49 Å. In the second Sm site, Sm(2) is bonded in a 3-coordinate geometry to one O(26), one O(33), and one O(36) atom. The Sm(2)-O(26) bond length is 2.29 Å. The Sm(2)-O(33) bond length is 2.31 Å. The Sm(2)-O(36) bond length is 2.26 Å. There are eleven inequivalent W sites. In the first W site, W(1) is bonded to one O(17), one O(18), one O(20), one O(21), and one O(34) atom to form distorted WO5 square pyramids that share  a cornercorner with one W(10)O6 octahedra,  a cornercorner with one W(2)O5 square pyramid,  an edgeedge with one W(3)O5 square pyramid, and  an edgeedge with one W(8)O5 square pyramid. The corner-sharing octahedral tilt angles are 33°. The W(1)-O(17) bond length is 1.92 Å. The W(1)-O(18) bond length is 2.36 Å. The W(1)-O(20) bond length is 2.00 Å. The W(1)-O(21) bond length is 1.90 Å. The W(1)-O(34) bond length is 1.90 Å. In the second W site, W(2) is bonded to one O(1), one O(10), one O(21), one O(23), and one O(3) atom to form distorted WO5 square pyramids that share  a cornercorner with one W(10)O6 octahedra,  a cornercorner with one W(1)O5 square pyramid, and  an edgeedge with one W(5)O5 square pyramid. The corner-sharing octahedral tilt angles are 30°. The W(2)-O(1) bond length is 1.89 Å. The W(2)-O(10) bond length is 1.91 Å. The W(2)-O(21) bond length is 1.92 Å. The W(2)-O(23) bond length is 1.88 Å. The W(2)-O(3) bond length is 2.44 Å. In the third W site, W(3) is bonded to one O(17), one O(18), one O(30), one O(8), and one O(9) atom to form distorted WO5 square pyramids that share  a cornercorner with one W(11)O6 octahedra,  an edgeedge with one W(1)O5 square pyramid, and  an edgeedge with one W(8)O5 square pyramid. The corner-sharing octahedral tilt angles are 34°. The W(3)-O(17) bond length is 1.91 Å. The W(3)-O(18) bond length is 2.29 Å. The W(3)-O(30) bond length is 1.96 Å. The W(3)-O(8) bond length is 1.88 Å. The W(3)-O(9) bond length is 1.97 Å. In the fourth W site, W(4) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(15), one O(19), one O(3), and one O(31) atom. The W(4)-O(10) bond length is 1.96 Å. The W(4)-O(12) bond length is 1.76 Å. The W(4)-O(15) bond length is 2.09 Å. The W(4)-O(19) bond length is 1.90 Å. The W(4)-O(3) bond length is 2.23 Å. The W(4)-O(31) bond length is 1.75 Å. In the fifth W site, W(5) is bonded to one O(15), one O(16), one O(23), one O(3), and one O(5) atom to form a mixture of distorted edge and corner-sharing WO5 square pyramids. The W(5)-O(15) bond length is 1.84 Å. The W(5)-O(16) bond length is 2.04 Å. The W(5)-O(23) bond length is 1.93 Å. The W(5)-O(3) bond length is 2.37 Å. The W(5)-O(5) bond length is 1.89 Å. In the sixth W site, W(6) is bonded to one O(11), one O(19), one O(2), one O(24), and one O(29) atom to form distorted edge-sharing WO5 square pyramids. The W(6)-O(11) bond length is 2.25 Å. The W(6)-O(19) bond length is 1.89 Å. The W(6)-O(2) bond length is 1.96 Å. The W(6)-O(24) bond length is 2.13 Å. The W(6)-O(29) bond length is 1.74 Å. In the seventh W site, W(7) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(2), one O(27), and one O(30) atom. The W(7)-O(11) bond length is 2.44 Å. The W(7)-O(14) bond length is 1.94 Å. The W(7)-O(2) bond length is 1.89 Å. The W(7)-O(27) bond length is 1.90 Å. The W(7)-O(30) bond length is 1.86 Å. In the eighth W site, W(8) is bonded to one O(16), one O(18), one O(25), one O(34), and one O(8) atom to form a mixture of edge and corner-sharing WO5 square pyramids. The W(8)-O(16) bond length is 1.79 Å. The W(8)-O(18) bond length is 2.30 Å. The W(8)-O(25) bond length is 1.86 Å. The W(8)-O(34) bond length is 2.02 Å. The W(8)-O(8) bond length is 2.01 Å. In the ninth W site, W(9) is bonded to one O(11), one O(14), one O(24), one O(25), and one O(5) atom to form a mixture of distorted edge and corner-sharing WO5 square pyramids. The W(9)-O(11) bond length is 2.41 Å. The W(9)-O(14) bond length is 1.91 Å. The W(9)-O(24) bond length is 1.81 Å. The W(9)-O(25) bond length is 1.98 Å. The W(9)-O(5) bond length is 1.91 Å. In the tenth W site, W(10) is bonded to one O(1), one O(20), one O(22), one O(28), one O(4), and one O(7) atom to form distorted WO6 octahedra that share  a cornercorner with one W(11)O6 octahedra,  a cornercorner with one W(1)O5 square pyramid,  a cornercorner with one W(2)O5 square pyramid,  a cornercorner with one P(1)CO3 tetrahedra, and  a cornercorner with one P(2)CO3 tetrahedra. The corner-sharing octahedral tilt angles are 27°. The W(10)-O(1) bond length is 1.92 Å. The W(10)-O(20) bond length is 1.81 Å. The W(10)-O(22) bond length is 1.99 Å. The W(10)-O(28) bond length is 1.74 Å. The W(10)-O(4) bond length is 2.13 Å. The W(10)-O(7) bond length is 1.91 Å. In the eleventh W site, W(11) is bonded to one O(13), one O(27), one O(32), one O(6), one O(7), and one O(9) atom to form distorted WO6 octahedra that share  a cornercorner with one W(10)O6 octahedra,  a cornercorner with one W(3)O5 square pyramid,  a cornercorner with one P(1)CO3 tetrahedra, and  a cornercorner with one P(2)CO3 tetrahedra. The corner-sharing octahedral tilt angles are 27°. The W(11)-O(13) bond length is 2.15 Å. The W(11)-O(27) bond length is 1.91 Å. The W(11)-O(32) bond length is 1.74 Å. The W(11)-O(6) bond length is 2.01 Å. The W(11)-O(7) bond length is 1.89 Å. The W(11)-O(9) bond length is 1.85 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted tetrahedral geometry to one C(2), one P(1), one P(2), and one O(35) atom. The C(1)-C(2) bond length is 1.45 Å. The C(1)-P(1) bond length is 1.84 Å. The C(1)-P(2) bond length is 1.82 Å. The C(1)-O(35) bond length is 1.37 Å. In the second C site, C(2) is bonded in a trigonal non-coplanar geometry to one C(1), one H(2), one H(3), and one H(4) atom. The C(2)-H(2) bond length is 0.96 Å. The C(2)-H(3) bond length is 0.96 Å. The C(2)-H(4) bond length is 0.96 Å. As(1) is bonded in a distorted T-shaped geometry to one O(11), one O(18), and one O(3) atom. The As(1)-O(11) bond length is 1.79 Å. The As(1)-O(18) bond length is 1.78 Å. The As(1)-O(3) bond length is 1.82 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one C(1), one O(13), one O(22), and one O(33) atom to form PCO3 tetrahedra that share  a cornercorner with one W(10)O6 octahedra,  a cornercorner with one W(11)O6 octahedra, and  a cornercorner with one P(2)CO3 tetrahedra. The corner-sharing octahedral tilt angles range from 45-49°. The P(1)-O(13) bond length is 1.54 Å. The P(1)-O(22) bond length is 1.56 Å. The P(1)-O(33) bond length is 1.52 Å. In the second P site, P(2) is bonded to one C(1), one O(26), one O(4), and one O(6) atom to form PCO3 tetrahedra that share  a cornercorner with one W(10)O6 octahedra,  a cornercorner with one W(11)O6 octahedra, and  a cornercorner with one P(1)CO3 tetrahedra. The corner-sharing octahedral tilt angles range from 45-50°. The P(2)-O(26) bond length is 1.56 Å. The P(2)-O(4) bond length is 1.59 Å. The P(2)-O(6) bond length is 1.54 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(35) atom. The H(1)-O(35) bond length is 0.82 Å. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(2) atom. There are thirty-seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one W(10) and one W(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one W(6) and one W(7) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one W(2), one W(4), one W(5), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one W(10) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one W(5) and one W(9) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one W(11) and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one W(10) and one W(11) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one W(3) and one W(8) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one W(11) and one W(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one W(2) and one W(4) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one W(6), one W(7), one W(9), and one As(1) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Sm(1) and one W(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one W(11) and one P(1) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one W(7) and one W(9) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one W(4) and one W(5) atom. In the sixteenth O site, O(16) is bonded in a bent 150 degrees geometry to one W(5) and one W(8) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one W(1) and one W(3) atom. In the eighteenth O site, O(18) is bonded in a distorted rectangular see-saw-like geometry to one W(1), one W(3), one W(8), and one As(1) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one W(4) and one W(6) atom. In the twentieth O site, O(20) is bonded in a bent 150 degrees geometry to one W(1) and one W(10) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one W(1) and one W(2) atom. In the twenty-second O site, O(22) is bonded in a distorted bent 150 degrees geometry to one W(10) and one P(1) atom. In the twenty-third O site, O(23) is bonded in a bent 120 degrees geometry to one W(2) and one W(5) atom. In the twenty-fourth O site, O(24) is bonded in a bent 120 degrees geometry to one W(6) and one W(9) atom. In the twenty-fifth O site, O(25) is bonded in a bent 150 degrees geometry to one W(8) and one W(9) atom. In the twenty-sixth O site, O(26) is bonded in a distorted single-bond geometry to one Sm(2) and one P(2) atom. In the twenty-seventh O site, O(27) is bonded in a bent 150 degrees geometry to one W(11) and one W(7) atom. In the twenty-eighth O site, O(28) is bonded in a distorted single-bond geometry to one Sm(1) and one W(10) atom. In the twenty-ninth O site, O(29) is bonded in a distorted bent 150 degrees geometry to one Sm(1) and one W(6) atom. In the thirtieth O site, O(30) is bonded in a bent 150 degrees geometry to one W(3) and one W(7) atom. In the thirty-first O site, O(31) is bonded in a distorted bent 150 degrees geometry to one Sm(1) and one W(4) atom. In the thirty-second O site, O(32) is bonded in a distorted single-bond geometry to one Sm(1) and one W(11) atom. In the thirty-third O site, O(33) is bonded in a distorted single-bond geometry to one Sm(2) and one P(1) atom. In the thirty-fourth O site, O(34) is bonded in a bent 120 degrees geometry to one W(1) and one W(8) atom. In the thirty-fifth O site, O(35) is bonded in a water-like geometry to one C(1) and one H(1) atom. In the thirty-sixth O site, O(36) is bonded in a water-like geometry to one Sm(2) and one O(37) atom. The O(36)-O(37) bond length is 1.02 Å. In the thirty-seventh O site, O(37) is bonded in a distorted single-bond geometry to one O(36) atom. Linkers: 4 CC(O)(P([O])([O])=O)P([O])([O])=O. Metal clusters: 8 [Sm] ,44 [W]. The MOF has largest included sphere 6.49 A, density 3.21 g/cm3, surface area 1128.47 m2/g, accessible volume 0.16 cm3/g