The crystal structure described by U3Sm6O17 crystallizes in the monoclinic C2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second U site, U(2) is bonded in a distorted body-centered cubic geometry to two equivalent O(4), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a body-centered cubic geometry to one O(1), one O(4), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. In the second Sm site, Sm(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form distorted corner-sharing SmO7 pentagonal bipyramids. In the third Sm site, Sm(3) is bonded in a 7-coordinate geometry to one O(1), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one U(1), one Sm(1), one Sm(2), and one Sm(3) atom to form distorted OSm3U tetrahedra that share  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with three equivalent O(4)Sm2U2 tetrahedra, corners with three equivalent O(5)Sm2U2 tetrahedra, corners with four equivalent O(3)Sm3U tetrahedra,  an edgeedge with one O(6)Sm2U2 tetrahedra,  an edgeedge with one O(7)Sm2U2 tetrahedra,  an edgeedge with one O(2)Sm3U tetrahedra, and  an edgeedge with one O(9)Sm4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one Sm(2), and two equivalent Sm(3) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm2U2 tetrahedra, corners with two equivalent O(1)Sm3U tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with three equivalent O(9)Sm4 tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra, and edges with three equivalent O(3)Sm3U tetrahedra. In the third O site, O(3) is bonded to one U(1), one Sm(2), and two equivalent Sm(3) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with four equivalent O(1)Sm3U tetrahedra,  an edgeedge with one O(7)Sm2U2 tetrahedra,  an edgeedge with one O(9)Sm4 tetrahedra, and edges with three equivalent O(2)Sm3U tetrahedra. In the fourth O site, O(4) is bonded to one U(1), one U(2), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with three equivalent O(1)Sm3U tetrahedra, corners with five equivalent O(5)Sm2U2 tetrahedra,  an edgeedge with one O(2)Sm3U tetrahedra, edges with two equivalent O(6)Sm2U2 tetrahedra, and edges with two equivalent O(7)Sm2U2 tetrahedra. In the fifth O site, O(5) is bonded to one U(1), one U(2), and two equivalent Sm(1) atoms to form distorted OSm2U2 tetrahedra that share  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(2)Sm3U tetrahedra,  a cornercorner with one O(3)Sm3U tetrahedra, corners with three equivalent O(5)Sm2U2 tetrahedra, corners with three equivalent O(1)Sm3U tetrahedra, corners with five equivalent O(4)Sm2U2 tetrahedra, edges with two equivalent O(7)Sm2U2 tetrahedra, and edges with three equivalent O(6)Sm2U2 tetrahedra. In the sixth O site, O(6) is bonded to one U(1), one U(2), and two equivalent Sm(1) atoms to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(1)Sm3U tetrahedra,  a cornercorner with one O(2)Sm3U tetrahedra,  a cornercorner with one O(3)Sm3U tetrahedra, corners with three equivalent O(6)Sm2U2 tetrahedra, corners with five equivalent O(7)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with three equivalent O(5)Sm2U2 tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one U(2), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(1)Sm3U tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with five equivalent O(6)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra,  an edgeedge with one O(3)Sm3U tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with two equivalent O(5)Sm2U2 tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sm(1), one Sm(2), and one Sm(3) atom. In the ninth O site, O(9) is bonded to two equivalent Sm(2) and two equivalent Sm(3) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with six equivalent O(2)Sm3U tetrahedra, edges with two equivalent O(1)Sm3U tetrahedra, and edges with two equivalent O(3)Sm3U tetrahedra. is represented by the CIF file [CIF]
data_Sm6U3O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.841
_cell_length_b   6.841
_cell_length_c   11.237
_cell_angle_alpha   73.534
_cell_angle_beta   73.534
_cell_angle_gamma   46.914
_symmetry_Int_Tables_number   1
_cell_volume   365.316
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sm  Sm0  1  0.018  0.646  0.383  1.0
  Sm  Sm1  1  0.683  0.314  0.176  1.0
  Sm  Sm2  1  0.300  0.046  0.943  1.0
  Sm  Sm3  1  0.954  0.700  0.057  1.0
  Sm  Sm4  1  0.686  0.317  0.824  1.0
  Sm  Sm5  1  0.354  0.982  0.617  1.0
  U  U6  1  0.027  0.654  0.720  1.0
  U  U7  1  0.675  0.325  0.500  1.0
  U  U8  1  0.346  0.973  0.280  1.0
  O  O9  1  0.680  0.952  0.234  1.0
  O  O10  1  0.247  0.444  0.882  1.0
  O  O11  1  0.743  0.908  0.862  1.0
  O  O12  1  0.048  0.320  0.766  1.0
  O  O13  1  0.439  0.557  0.648  1.0
  O  O14  1  0.776  0.877  0.576  1.0
  O  O15  1  0.302  0.382  0.555  1.0
  O  O16  1  0.123  0.224  0.424  1.0
  O  O17  1  0.923  0.065  0.353  1.0
  O  O18  1  0.443  0.561  0.352  1.0
  O  O19  1  0.244  0.530  0.186  1.0
  O  O20  1  0.556  0.753  0.118  1.0
  O  O21  1  0.092  0.257  0.138  1.0
  O  O22  1  0.901  0.099  0.000  1.0
  O  O23  1  0.470  0.756  0.814  1.0
  O  O24  1  0.935  0.077  0.647  1.0
  O  O25  1  0.618  0.698  0.445  1.0
[/CIF]
.
The crystal structure described by U3Sm6O17 crystallizes in the monoclinic C2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the second U site, U(2) is bonded in a distorted body-centered cubic geometry to two equivalent O(4), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a body-centered cubic geometry to one O(1), one O(4), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. In the second Sm site, Sm(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(7), one O(8), and one O(9) atom to form distorted corner-sharing SmO7 pentagonal bipyramids. In the third Sm site, Sm(3) is bonded in a 7-coordinate geometry to one O(1), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one U(1), one Sm(1), one Sm(2), and one Sm(3) atom to form distorted OSm3U tetrahedra that share  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with three equivalent O(4)Sm2U2 tetrahedra, corners with three equivalent O(5)Sm2U2 tetrahedra, corners with four equivalent O(3)Sm3U tetrahedra,  an edgeedge with one O(6)Sm2U2 tetrahedra,  an edgeedge with one O(7)Sm2U2 tetrahedra,  an edgeedge with one O(2)Sm3U tetrahedra, and  an edgeedge with one O(9)Sm4 tetrahedra. In the second O site, O(2) is bonded to one U(1), one Sm(2), and two equivalent Sm(3) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm2U2 tetrahedra, corners with two equivalent O(1)Sm3U tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with three equivalent O(9)Sm4 tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra, and edges with three equivalent O(3)Sm3U tetrahedra. In the third O site, O(3) is bonded to one U(1), one Sm(2), and two equivalent Sm(3) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with four equivalent O(1)Sm3U tetrahedra,  an edgeedge with one O(7)Sm2U2 tetrahedra,  an edgeedge with one O(9)Sm4 tetrahedra, and edges with three equivalent O(2)Sm3U tetrahedra. In the fourth O site, O(4) is bonded to one U(1), one U(2), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with three equivalent O(1)Sm3U tetrahedra, corners with five equivalent O(5)Sm2U2 tetrahedra,  an edgeedge with one O(2)Sm3U tetrahedra, edges with two equivalent O(6)Sm2U2 tetrahedra, and edges with two equivalent O(7)Sm2U2 tetrahedra. In the fifth O site, O(5) is bonded to one U(1), one U(2), and two equivalent Sm(1) atoms to form distorted OSm2U2 tetrahedra that share  a cornercorner with one O(6)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(2)Sm3U tetrahedra,  a cornercorner with one O(3)Sm3U tetrahedra, corners with three equivalent O(5)Sm2U2 tetrahedra, corners with three equivalent O(1)Sm3U tetrahedra, corners with five equivalent O(4)Sm2U2 tetrahedra, edges with two equivalent O(7)Sm2U2 tetrahedra, and edges with three equivalent O(6)Sm2U2 tetrahedra. In the sixth O site, O(6) is bonded to one U(1), one U(2), and two equivalent Sm(1) atoms to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(1)Sm3U tetrahedra,  a cornercorner with one O(2)Sm3U tetrahedra,  a cornercorner with one O(3)Sm3U tetrahedra, corners with three equivalent O(6)Sm2U2 tetrahedra, corners with five equivalent O(7)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with three equivalent O(5)Sm2U2 tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one U(2), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra,  a cornercorner with one O(5)Sm2U2 tetrahedra,  a cornercorner with one O(7)Sm2U2 tetrahedra,  a cornercorner with one O(1)Sm3U tetrahedra,  a cornercorner with one O(9)Sm4 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with five equivalent O(6)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm3U tetrahedra,  an edgeedge with one O(3)Sm3U tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with two equivalent O(5)Sm2U2 tetrahedra. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Sm(1), one Sm(2), and one Sm(3) atom. In the ninth O site, O(9) is bonded to two equivalent Sm(2) and two equivalent Sm(3) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm3U tetrahedra, corners with six equivalent O(2)Sm3U tetrahedra, edges with two equivalent O(1)Sm3U tetrahedra, and edges with two equivalent O(3)Sm3U tetrahedra. is represented by the CIF file [CIF]
data_Sm6U3O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.841
_cell_length_b   6.841
_cell_length_c   11.237
_cell_angle_alpha   73.534
_cell_angle_beta   73.534
_cell_angle_gamma   46.914
_symmetry_Int_Tables_number   1
_cell_volume   365.316
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sm  Sm0  1  0.018  0.646  0.383  1.0
  Sm  Sm1  1  0.683  0.314  0.176  1.0
  Sm  Sm2  1  0.300  0.046  0.943  1.0
  Sm  Sm3  1  0.954  0.700  0.057  1.0
  Sm  Sm4  1  0.686  0.317  0.824  1.0
  Sm  Sm5  1  0.354  0.982  0.617  1.0
  U  U6  1  0.027  0.654  0.720  1.0
  U  U7  1  0.675  0.325  0.500  1.0
  U  U8  1  0.346  0.973  0.280  1.0
  O  O9  1  0.680  0.952  0.234  1.0
  O  O10  1  0.247  0.444  0.882  1.0
  O  O11  1  0.743  0.908  0.862  1.0
  O  O12  1  0.048  0.320  0.766  1.0
  O  O13  1  0.439  0.557  0.648  1.0
  O  O14  1  0.776  0.877  0.576  1.0
  O  O15  1  0.302  0.382  0.555  1.0
  O  O16  1  0.123  0.224  0.424  1.0
  O  O17  1  0.923  0.065  0.353  1.0
  O  O18  1  0.443  0.561  0.352  1.0
  O  O19  1  0.244  0.530  0.186  1.0
  O  O20  1  0.556  0.753  0.118  1.0
  O  O21  1  0.092  0.257  0.138  1.0
  O  O22  1  0.901  0.099  0.000  1.0
  O  O23  1  0.470  0.756  0.814  1.0
  O  O24  1  0.935  0.077  0.647  1.0
  O  O25  1  0.618  0.698  0.445  1.0
[/CIF]
.