The crystal structure described by Sr3Hf2O7 crystallizes in the orthorhombic Ccce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded to four O(3,3) and eight equivalent O(2) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, and faces with eight equivalent Hf(1)O6 octahedra. Hf(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form HfO6 octahedra that share corners with five equivalent Hf(1)O6 octahedra and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-22°. There are five inequivalent O sites. In the first O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(1) is bonded to five equivalent Sr(1) and one Hf(1) atom to form distorted OSr5Hf octahedra that share  a cornercorner with one O(3)Sr4Hf2 octahedra, corners with four equivalent O(1)Sr5Hf octahedra, and edges with eight equivalent O(1)Sr5Hf octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Hf(1) atoms. In the fifth O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3Hf2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.005
_cell_length_b   11.005
_cell_length_c   5.714
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   149.903
_symmetry_Int_Tables_number   1
_cell_volume   347.017
_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
  Sr  Sr0  1  0.188  0.812  0.500  1.0
  Sr  Sr1  1  0.812  0.188  0.500  1.0
  Sr  Sr2  1  0.688  0.312  0.000  1.0
  Sr  Sr3  1  0.000  0.000  0.500  1.0
  Sr  Sr4  1  0.500  0.500  0.000  1.0
  Sr  Sr5  1  0.312  0.688  0.000  1.0
  Hf  Hf6  1  0.098  0.902  0.000  1.0
  Hf  Hf7  1  0.598  0.402  0.500  1.0
  Hf  Hf8  1  0.902  0.098  0.000  1.0
  Hf  Hf9  1  0.402  0.598  0.500  1.0
  O  O10  1  0.196  0.804  0.000  1.0
  O  O11  1  0.605  0.798  0.202  1.0
  O  O12  1  0.298  0.105  0.702  1.0
  O  O13  1  0.702  0.895  0.702  1.0
  O  O14  1  0.395  0.202  0.202  1.0
  O  O15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.696  0.304  0.500  1.0
  O  O17  1  0.804  0.196  0.000  1.0
  O  O18  1  0.105  0.298  0.298  1.0
  O  O19  1  0.798  0.605  0.798  1.0
  O  O20  1  0.895  0.702  0.298  1.0
  O  O21  1  0.202  0.395  0.798  1.0
  O  O22  1  0.500  0.500  0.500  1.0
  O  O23  1  0.304  0.696  0.500  1.0
[/CIF]
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The crystal structure described by Sr3Hf2O7 crystallizes in the orthorhombic Ccce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded to four O(3,3) and eight equivalent O(2) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, and faces with eight equivalent Hf(1)O6 octahedra. Hf(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form HfO6 octahedra that share corners with five equivalent Hf(1)O6 octahedra and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-22°. There are five inequivalent O sites. In the first O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(1) is bonded to five equivalent Sr(1) and one Hf(1) atom to form distorted OSr5Hf octahedra that share  a cornercorner with one O(3)Sr4Hf2 octahedra, corners with four equivalent O(1)Sr5Hf octahedra, and edges with eight equivalent O(1)Sr5Hf octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Hf(1) atoms. In the fifth O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Hf(1) atoms to form distorted OSr4Hf2 octahedra that share corners with two equivalent O(1)Sr5Hf octahedra, corners with four equivalent O(3)Sr4Hf2 octahedra, and edges with four equivalent O(3)Sr4Hf2 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr3Hf2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.005
_cell_length_b   11.005
_cell_length_c   5.714
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   149.903
_symmetry_Int_Tables_number   1
_cell_volume   347.017
_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
  Sr  Sr0  1  0.188  0.812  0.500  1.0
  Sr  Sr1  1  0.812  0.188  0.500  1.0
  Sr  Sr2  1  0.688  0.312  0.000  1.0
  Sr  Sr3  1  0.000  0.000  0.500  1.0
  Sr  Sr4  1  0.500  0.500  0.000  1.0
  Sr  Sr5  1  0.312  0.688  0.000  1.0
  Hf  Hf6  1  0.098  0.902  0.000  1.0
  Hf  Hf7  1  0.598  0.402  0.500  1.0
  Hf  Hf8  1  0.902  0.098  0.000  1.0
  Hf  Hf9  1  0.402  0.598  0.500  1.0
  O  O10  1  0.196  0.804  0.000  1.0
  O  O11  1  0.605  0.798  0.202  1.0
  O  O12  1  0.298  0.105  0.702  1.0
  O  O13  1  0.702  0.895  0.702  1.0
  O  O14  1  0.395  0.202  0.202  1.0
  O  O15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.696  0.304  0.500  1.0
  O  O17  1  0.804  0.196  0.000  1.0
  O  O18  1  0.105  0.298  0.298  1.0
  O  O19  1  0.798  0.605  0.798  1.0
  O  O20  1  0.895  0.702  0.298  1.0
  O  O21  1  0.202  0.395  0.798  1.0
  O  O22  1  0.500  0.500  0.500  1.0
  O  O23  1  0.304  0.696  0.500  1.0
[/CIF]
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