The material structure described by Sm2O3 crystallizes in the monoclinic C2/m space group. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(3), two equivalent O(5), and three equivalent O(4) atoms. In the third Sm site, Sm(3) is bonded in a 7-coordinate geometry to two equivalent O(2), two equivalent O(5), and three equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(2) and four equivalent Sm(1) atoms to form OSm6 octahedra that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(2)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra, edges with four equivalent O(5)Sm5 square pyramids, edges with two equivalent O(2)Sm4 tetrahedra, and edges with four equivalent O(4)Sm4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(3) atoms to form OSm4 tetrahedra that share corners with two equivalent O(1)Sm6 octahedra, corners with two equivalent O(5)Sm5 square pyramids, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra,  an edgeedge with one O(1)Sm6 octahedra, edges with two equivalent O(5)Sm5 square pyramids, and  an edgeedge with one O(2)Sm4 tetrahedra. The corner-sharing octahedral tilt angles are 15°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(2) and three equivalent Sm(3) atoms. In the fourth O site, O(4) is bonded to one Sm(1) and three equivalent Sm(2) atoms to form OSm4 tetrahedra that share  a cornercorner with one O(1)Sm6 octahedra, corners with five equivalent O(5)Sm5 square pyramids, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra,  an edgeedge with one O(5)Sm5 square pyramid, and edges with two equivalent O(4)Sm4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the fifth O site, O(5) is bonded to one Sm(1), two equivalent Sm(2), and two equivalent Sm(3) atoms to form distorted OSm5 square pyramids that share corners with two equivalent O(2)Sm4 tetrahedra, corners with five equivalent O(4)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra, edges with two equivalent O(5)Sm5 square pyramids,  an edgeedge with one O(4)Sm4 tetrahedra, and edges with two equivalent O(2)Sm4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.618
_cell_length_b   7.336
_cell_length_c   8.860
_cell_angle_alpha   99.566
_cell_angle_beta   90.000
_cell_angle_gamma   104.277
_symmetry_Int_Tables_number   1
_cell_volume   224.530
_cell_formula_units_Z   3
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  0.034  0.068  0.812  1.0
  Sm  Sm1  1  0.966  0.932  0.188  1.0
  Sm  Sm2  1  0.310  0.620  0.862  1.0
  Sm  Sm3  1  0.690  0.380  0.138  1.0
  Sm  Sm4  1  0.365  0.730  0.512  1.0
  Sm  Sm5  1  0.635  0.270  0.488  1.0
  O  O6  1  0.500  0.000  0.000  1.0
  O  O7  1  0.527  0.054  0.656  1.0
  O  O8  1  0.473  0.946  0.344  1.0
  O  O9  1  0.203  0.407  0.626  1.0
  O  O10  1  0.797  0.593  0.374  1.0
  O  O11  1  0.175  0.351  0.972  1.0
  O  O12  1  0.129  0.258  0.285  1.0
  O  O13  1  0.871  0.742  0.715  1.0
  O  O14  1  0.825  0.649  0.028  1.0
[/CIF]
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The material structure described by Sm2O3 crystallizes in the monoclinic C2/m space group. There are three inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(1), and two equivalent O(2) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(3), two equivalent O(5), and three equivalent O(4) atoms. In the third Sm site, Sm(3) is bonded in a 7-coordinate geometry to two equivalent O(2), two equivalent O(5), and three equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(2) and four equivalent Sm(1) atoms to form OSm6 octahedra that share corners with two equivalent O(4)Sm4 tetrahedra, corners with four equivalent O(2)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra, edges with four equivalent O(5)Sm5 square pyramids, edges with two equivalent O(2)Sm4 tetrahedra, and edges with four equivalent O(4)Sm4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(3) atoms to form OSm4 tetrahedra that share corners with two equivalent O(1)Sm6 octahedra, corners with two equivalent O(5)Sm5 square pyramids, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra,  an edgeedge with one O(1)Sm6 octahedra, edges with two equivalent O(5)Sm5 square pyramids, and  an edgeedge with one O(2)Sm4 tetrahedra. The corner-sharing octahedral tilt angles are 15°. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(2) and three equivalent Sm(3) atoms. In the fourth O site, O(4) is bonded to one Sm(1) and three equivalent Sm(2) atoms to form OSm4 tetrahedra that share  a cornercorner with one O(1)Sm6 octahedra, corners with five equivalent O(5)Sm5 square pyramids, corners with two equivalent O(2)Sm4 tetrahedra, corners with two equivalent O(4)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra,  an edgeedge with one O(5)Sm5 square pyramid, and edges with two equivalent O(4)Sm4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the fifth O site, O(5) is bonded to one Sm(1), two equivalent Sm(2), and two equivalent Sm(3) atoms to form distorted OSm5 square pyramids that share corners with two equivalent O(2)Sm4 tetrahedra, corners with five equivalent O(4)Sm4 tetrahedra, edges with two equivalent O(1)Sm6 octahedra, edges with two equivalent O(5)Sm5 square pyramids,  an edgeedge with one O(4)Sm4 tetrahedra, and edges with two equivalent O(2)Sm4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.618
_cell_length_b   7.336
_cell_length_c   8.860
_cell_angle_alpha   99.566
_cell_angle_beta   90.000
_cell_angle_gamma   104.277
_symmetry_Int_Tables_number   1
_cell_volume   224.530
_cell_formula_units_Z   3
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  0.034  0.068  0.812  1.0
  Sm  Sm1  1  0.966  0.932  0.188  1.0
  Sm  Sm2  1  0.310  0.620  0.862  1.0
  Sm  Sm3  1  0.690  0.380  0.138  1.0
  Sm  Sm4  1  0.365  0.730  0.512  1.0
  Sm  Sm5  1  0.635  0.270  0.488  1.0
  O  O6  1  0.500  0.000  0.000  1.0
  O  O7  1  0.527  0.054  0.656  1.0
  O  O8  1  0.473  0.946  0.344  1.0
  O  O9  1  0.203  0.407  0.626  1.0
  O  O10  1  0.797  0.593  0.374  1.0
  O  O11  1  0.175  0.351  0.972  1.0
  O  O12  1  0.129  0.258  0.285  1.0
  O  O13  1  0.871  0.742  0.715  1.0
  O  O14  1  0.825  0.649  0.028  1.0
[/CIF]
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