MgSm4(HO2)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 3-coordinate geometry to one H(2), one O(1), and one O(6) atom. There are four inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 5-coordinate geometry to one O(7), two equivalent O(3), and two equivalent O(8) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(6), two equivalent O(2), and two equivalent O(5) atoms. In the third Sm site, Sm(3) is bonded in a 6-coordinate geometry to one O(3), one O(5), two equivalent O(4), and two equivalent O(7) atoms. In the fourth Sm site, Sm(4) is bonded in a 6-coordinate geometry to one O(2), one O(8), two equivalent O(1), and two equivalent O(6) atoms. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one Mg(1) and one O(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(5) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mg(1), one Sm(2), two equivalent Sm(4), and one H(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Sm(4) and two equivalent Sm(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Sm(3) and two equivalent Sm(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Sm(2), two equivalent Sm(3), and one H(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sm(3), two equivalent Sm(2), and one H(4) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Sm(2), and two equivalent Sm(4) atoms to form corner-sharing OSm3Mg tetrahedra. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Sm(1) and two equivalent Sm(3) atoms. In the eighth O site, O(8) is bonded in a single-bond geometry to one Sm(4), two equivalent Sm(1), and one H(3) atom.
MgSm4(HO2)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 3-coordinate geometry to one H(2), one O(1), and one O(6) atom. The Mg(1)-H(2) bond length is 2.20 Å. The Mg(1)-O(1) bond length is 2.12 Å. The Mg(1)-O(6) bond length is 2.07 Å. There are four inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 5-coordinate geometry to one O(7), two equivalent O(3), and two equivalent O(8) atoms. The Sm(1)-O(7) bond length is 2.22 Å. Both Sm(1)-O(3) bond lengths are 2.26 Å. Both Sm(1)-O(8) bond lengths are 2.60 Å. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(4), one O(6), two equivalent O(2), and two equivalent O(5) atoms. The Sm(2)-O(1) bond length is 2.71 Å. The Sm(2)-O(4) bond length is 2.36 Å. The Sm(2)-O(6) bond length is 2.35 Å. Both Sm(2)-O(2) bond lengths are 2.29 Å. Both Sm(2)-O(5) bond lengths are 2.55 Å. In the third Sm site, Sm(3) is bonded in a 6-coordinate geometry to one O(3), one O(5), two equivalent O(4), and two equivalent O(7) atoms. The Sm(3)-O(3) bond length is 2.23 Å. The Sm(3)-O(5) bond length is 2.54 Å. Both Sm(3)-O(4) bond lengths are 2.48 Å. Both Sm(3)-O(7) bond lengths are 2.31 Å. In the fourth Sm site, Sm(4) is bonded in a 6-coordinate geometry to one O(2), one O(8), two equivalent O(1), and two equivalent O(6) atoms. The Sm(4)-O(2) bond length is 2.23 Å. The Sm(4)-O(8) bond length is 2.57 Å. Both Sm(4)-O(1) bond lengths are 2.46 Å. Both Sm(4)-O(6) bond lengths are 2.31 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.97 Å. In the second H site, H(2) is bonded in a single-bond geometry to one Mg(1) and one O(1) atom. The H(2)-O(1) bond length is 0.99 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. 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 O(5) atom. The H(4)-O(5) bond length is 0.98 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Mg(1), one Sm(2), two equivalent Sm(4), and one H(2) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Sm(4) and two equivalent Sm(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Sm(3) and two equivalent Sm(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Sm(2), two equivalent Sm(3), and one H(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Sm(3), two equivalent Sm(2), and one H(4) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Sm(2), and two equivalent Sm(4) atoms to form corner-sharing OSm3Mg tetrahedra. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Sm(1) and two equivalent Sm(3) atoms. In the eighth O site, O(8) is bonded in a single-bond geometry to one Sm(4), two equivalent Sm(1), and one H(3) atom.