Pr3Mn2Sb3O14 crystallizes in the trigonal R-3m space group. Pr(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to six equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted MnO8 hexagonal bipyramids that share edges with six equivalent Sb(1)O6 octahedra. Sb(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and edges with two equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-55°. There are three inequivalent O sites. In the first O site, O(3) is bonded to two equivalent Pr(1), one Mn(1), and one Sb(1) atom to form distorted OPr2MnSb tetrahedra that share corners with two equivalent O(1)Pr3Mn tetrahedra, corners with eight equivalent O(3)Pr2MnSb tetrahedra, corners with four equivalent O(2)PrMnSb2 trigonal pyramids,  an edgeedge with one O(1)Pr3Mn tetrahedra, edges with two equivalent O(3)Pr2MnSb tetrahedra, and edges with two equivalent O(2)PrMnSb2 trigonal pyramids. In the second O site, O(1) is bonded to three equivalent Pr(1) and one Mn(2) atom to form OPr3Mn tetrahedra that share corners with four equivalent O(1)Pr3Mn tetrahedra, corners with six equivalent O(3)Pr2MnSb tetrahedra, corners with six equivalent O(2)PrMnSb2 trigonal pyramids, edges with three equivalent O(3)Pr2MnSb tetrahedra, and edges with three equivalent O(2)PrMnSb2 trigonal pyramids. In the third O site, O(2) is bonded to one Pr(1), one Mn(2), and two equivalent Sb(1) atoms to form distorted OPrMnSb2 trigonal pyramids that share corners with two equivalent O(1)Pr3Mn tetrahedra, corners with four equivalent O(3)Pr2MnSb tetrahedra, corners with eight equivalent O(2)PrMnSb2 trigonal pyramids,  an edgeedge with one O(1)Pr3Mn tetrahedra, edges with two equivalent O(3)Pr2MnSb tetrahedra, and edges with two equivalent O(2)PrMnSb2 trigonal pyramids.
Pr3Mn2Sb3O14 crystallizes in the trigonal R-3m space group. Pr(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Pr(1)-O(1) bond lengths are 2.38 Å. Both Pr(1)-O(2) bond lengths are 2.66 Å. All Pr(1)-O(3) bond lengths are 2.55 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to six equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. All Mn(1)-O(3) bond lengths are 2.21 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1) and six equivalent O(2) atoms to form distorted MnO8 hexagonal bipyramids that share edges with six equivalent Sb(1)O6 octahedra. Both Mn(2)-O(1) bond lengths are 2.06 Å. All Mn(2)-O(2) bond lengths are 2.66 Å. Sb(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and edges with two equivalent Mn(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-55°. Both Sb(1)-O(3) bond lengths are 1.97 Å. All Sb(1)-O(2) bond lengths are 2.04 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded to two equivalent Pr(1), one Mn(1), and one Sb(1) atom to form distorted OPr2MnSb tetrahedra that share corners with two equivalent O(1)Pr3Mn tetrahedra, corners with eight equivalent O(3)Pr2MnSb tetrahedra, corners with four equivalent O(2)PrMnSb2 trigonal pyramids,  an edgeedge with one O(1)Pr3Mn tetrahedra, edges with two equivalent O(3)Pr2MnSb tetrahedra, and edges with two equivalent O(2)PrMnSb2 trigonal pyramids. In the second O site, O(1) is bonded to three equivalent Pr(1) and one Mn(2) atom to form OPr3Mn tetrahedra that share corners with four equivalent O(1)Pr3Mn tetrahedra, corners with six equivalent O(3)Pr2MnSb tetrahedra, corners with six equivalent O(2)PrMnSb2 trigonal pyramids, edges with three equivalent O(3)Pr2MnSb tetrahedra, and edges with three equivalent O(2)PrMnSb2 trigonal pyramids. In the third O site, O(2) is bonded to one Pr(1), one Mn(2), and two equivalent Sb(1) atoms to form distorted OPrMnSb2 trigonal pyramids that share corners with two equivalent O(1)Pr3Mn tetrahedra, corners with four equivalent O(3)Pr2MnSb tetrahedra, corners with eight equivalent O(2)PrMnSb2 trigonal pyramids,  an edgeedge with one O(1)Pr3Mn tetrahedra, edges with two equivalent O(3)Pr2MnSb tetrahedra, and edges with two equivalent O(2)PrMnSb2 trigonal pyramids.