The crystal structure described by Sm2Hf2O7 crystallizes in the cubic Fd-3m space group. Sm(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(2) and six equivalent O(1) atoms. Hf(1) is bonded to six equivalent O(1) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Hf(1) atoms to form distorted OSm2Hf2 tetrahedra that share corners with two equivalent O(2)Sm4 tetrahedra, corners with twelve equivalent O(1)Sm2Hf2 tetrahedra,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with four equivalent O(1)Sm2Hf2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Sm(1) atoms to form OSm4 tetrahedra that share corners with four equivalent O(2)Sm4 tetrahedra, corners with twelve equivalent O(1)Sm2Hf2 tetrahedra, and edges with six equivalent O(1)Sm2Hf2 tetrahedra. is represented by the CIF file [CIF]
data_Sm2Hf2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.466
_cell_length_b   7.466
_cell_length_c   7.466
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   294.257
_cell_formula_units_Z   2
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  0.625  0.125  0.125  1.0
  Sm  Sm1  1  0.125  0.625  0.125  1.0
  Sm  Sm2  1  0.125  0.125  0.625  1.0
  Sm  Sm3  1  0.125  0.125  0.125  1.0
  Hf  Hf4  1  0.125  0.625  0.625  1.0
  Hf  Hf5  1  0.625  0.125  0.625  1.0
  Hf  Hf6  1  0.625  0.625  0.125  1.0
  Hf  Hf7  1  0.625  0.625  0.625  1.0
  O  O8  1  0.709  0.709  0.291  1.0
  O  O9  1  0.291  0.291  0.709  1.0
  O  O10  1  0.709  0.291  0.709  1.0
  O  O11  1  0.291  0.709  0.291  1.0
  O  O12  1  0.291  0.709  0.709  1.0
  O  O13  1  0.709  0.291  0.291  1.0
  O  O14  1  0.541  0.541  0.959  1.0
  O  O15  1  0.959  0.959  0.541  1.0
  O  O16  1  0.541  0.959  0.541  1.0
  O  O17  1  0.959  0.541  0.959  1.0
  O  O18  1  0.959  0.541  0.541  1.0
  O  O19  1  0.541  0.959  0.959  1.0
  O  O20  1  0.250  0.250  0.250  1.0
  O  O21  1  0.000  0.000  0.000  1.0
[/CIF]
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The crystal structure described by Sm2Hf2O7 crystallizes in the cubic Fd-3m space group. Sm(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(2) and six equivalent O(1) atoms. Hf(1) is bonded to six equivalent O(1) atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Hf(1) atoms to form distorted OSm2Hf2 tetrahedra that share corners with two equivalent O(2)Sm4 tetrahedra, corners with twelve equivalent O(1)Sm2Hf2 tetrahedra,  an edgeedge with one O(2)Sm4 tetrahedra, and edges with four equivalent O(1)Sm2Hf2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Sm(1) atoms to form OSm4 tetrahedra that share corners with four equivalent O(2)Sm4 tetrahedra, corners with twelve equivalent O(1)Sm2Hf2 tetrahedra, and edges with six equivalent O(1)Sm2Hf2 tetrahedra. is represented by the CIF file [CIF]
data_Sm2Hf2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.466
_cell_length_b   7.466
_cell_length_c   7.466
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   294.257
_cell_formula_units_Z   2
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  0.625  0.125  0.125  1.0
  Sm  Sm1  1  0.125  0.625  0.125  1.0
  Sm  Sm2  1  0.125  0.125  0.625  1.0
  Sm  Sm3  1  0.125  0.125  0.125  1.0
  Hf  Hf4  1  0.125  0.625  0.625  1.0
  Hf  Hf5  1  0.625  0.125  0.625  1.0
  Hf  Hf6  1  0.625  0.625  0.125  1.0
  Hf  Hf7  1  0.625  0.625  0.625  1.0
  O  O8  1  0.709  0.709  0.291  1.0
  O  O9  1  0.291  0.291  0.709  1.0
  O  O10  1  0.709  0.291  0.709  1.0
  O  O11  1  0.291  0.709  0.291  1.0
  O  O12  1  0.291  0.709  0.709  1.0
  O  O13  1  0.709  0.291  0.291  1.0
  O  O14  1  0.541  0.541  0.959  1.0
  O  O15  1  0.959  0.959  0.541  1.0
  O  O16  1  0.541  0.959  0.541  1.0
  O  O17  1  0.959  0.541  0.959  1.0
  O  O18  1  0.959  0.541  0.541  1.0
  O  O19  1  0.541  0.959  0.959  1.0
  O  O20  1  0.250  0.250  0.250  1.0
  O  O21  1  0.000  0.000  0.000  1.0
[/CIF]
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