The crystal structure described by SrCaU2O8 crystallizes in the trigonal R-3m space group. Sr(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six O(3,3) atoms. Ca(1) is bonded in a body-centered cubic geometry to two equivalent O(2) and six equivalent O(4) atoms. U(1) is bonded in a distorted body-centered cubic geometry to one O(3), one O(4), three equivalent O(1), and three equivalent O(2) atoms. There are seven inequivalent O sites. In the first O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(3,3)Sr3U tetrahedra; edges with three equivalent O(3)Sr3U tetrahedra; and edges with three equivalent O(1)SrU3 tetrahedra. In the second O site, O(1) is bonded to one Sr(1) and three equivalent U(1) atoms to form OSrU3 tetrahedra that share corners with three equivalent O(4)Ca3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(3)Sr3U tetrahedra, corners with seven equivalent O(1)SrU3 tetrahedra, edges with three equivalent O(2)CaU3 tetrahedra, and edges with three equivalent O(3)Sr3U tetrahedra. In the third O site, O(2) is bonded to one Ca(1) and three equivalent U(1) atoms to form OCaU3 tetrahedra that share corners with three equivalent O(4)Ca3U tetrahedra, corners with three equivalent O(3)Sr3U tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with seven equivalent O(2)CaU3 tetrahedra, edges with three equivalent O(4)Ca3U tetrahedra, and edges with three equivalent O(1)SrU3 tetrahedra. In the fourth O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(3,3)Sr3U tetrahedra; edges with three equivalent O(3)Sr3U tetrahedra; and edges with three equivalent O(1)SrU3 tetrahedra. In the fifth O site, O(4) is bonded to three equivalent Ca(1) and one U(1) atom to form OCa3U tetrahedra that share  a cornercorner with one O(3)Sr3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with nine equivalent O(4)Ca3U tetrahedra, edges with three equivalent O(4)Ca3U tetrahedra, and edges with three equivalent O(2)CaU3 tetrahedra. In the sixth O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with nine equivalent O(3)Sr3U tetrahedra, edges with three equivalent O(3)Sr3U tetrahedra, and edges with three equivalent O(1)SrU3 tetrahedra. In the seventh O site, O(4) is bonded to three equivalent Ca(1) and one U(1) atom to form OCa3U tetrahedra that share  a cornercorner with one O(3)Sr3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(4,4)Ca3U tetrahedra; edges with three equivalent O(4)Ca3U tetrahedra; and edges with three equivalent O(2)CaU3 tetrahedra. is represented by the CIF card [CIF]
data_SrCaU2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.440
_cell_length_b   12.440
_cell_length_c   12.440
_cell_angle_alpha   18.093
_cell_angle_beta   18.093
_cell_angle_gamma   18.093
_symmetry_Int_Tables_number   1
_cell_volume   162.157
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.500  0.500  0.500  1.0
  U  U2  1  0.752  0.752  0.752  1.0
  U  U3  1  0.248  0.248  0.248  1.0
  O  O4  1  0.072  0.072  0.072  1.0
  O  O5  1  0.567  0.567  0.567  1.0
  O  O6  1  0.928  0.928  0.928  1.0
  O  O7  1  0.433  0.433  0.433  1.0
  O  O8  1  0.698  0.698  0.698  1.0
  O  O9  1  0.194  0.194  0.194  1.0
  O  O10  1  0.302  0.302  0.302  1.0
  O  O11  1  0.806  0.806  0.806  1.0
[/CIF]
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The crystal structure described by SrCaU2O8 crystallizes in the trigonal R-3m space group. Sr(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six O(3,3) atoms. Ca(1) is bonded in a body-centered cubic geometry to two equivalent O(2) and six equivalent O(4) atoms. U(1) is bonded in a distorted body-centered cubic geometry to one O(3), one O(4), three equivalent O(1), and three equivalent O(2) atoms. There are seven inequivalent O sites. In the first O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(3,3)Sr3U tetrahedra; edges with three equivalent O(3)Sr3U tetrahedra; and edges with three equivalent O(1)SrU3 tetrahedra. In the second O site, O(1) is bonded to one Sr(1) and three equivalent U(1) atoms to form OSrU3 tetrahedra that share corners with three equivalent O(4)Ca3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(3)Sr3U tetrahedra, corners with seven equivalent O(1)SrU3 tetrahedra, edges with three equivalent O(2)CaU3 tetrahedra, and edges with three equivalent O(3)Sr3U tetrahedra. In the third O site, O(2) is bonded to one Ca(1) and three equivalent U(1) atoms to form OCaU3 tetrahedra that share corners with three equivalent O(4)Ca3U tetrahedra, corners with three equivalent O(3)Sr3U tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with seven equivalent O(2)CaU3 tetrahedra, edges with three equivalent O(4)Ca3U tetrahedra, and edges with three equivalent O(1)SrU3 tetrahedra. In the fourth O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(3,3)Sr3U tetrahedra; edges with three equivalent O(3)Sr3U tetrahedra; and edges with three equivalent O(1)SrU3 tetrahedra. In the fifth O site, O(4) is bonded to three equivalent Ca(1) and one U(1) atom to form OCa3U tetrahedra that share  a cornercorner with one O(3)Sr3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with nine equivalent O(4)Ca3U tetrahedra, edges with three equivalent O(4)Ca3U tetrahedra, and edges with three equivalent O(2)CaU3 tetrahedra. In the sixth O site, O(3) is bonded to three equivalent Sr(1) and one U(1) atom to form distorted OSr3U tetrahedra that share  a cornercorner with one O(4)Ca3U tetrahedra, corners with three equivalent O(2)CaU3 tetrahedra, corners with three equivalent O(1)SrU3 tetrahedra, corners with nine equivalent O(3)Sr3U tetrahedra, edges with three equivalent O(3)Sr3U tetrahedra, and edges with three equivalent O(1)SrU3 tetrahedra. In the seventh O site, O(4) is bonded to three equivalent Ca(1) and one U(1) atom to form OCa3U tetrahedra that share  a cornercorner with one O(3)Sr3U tetrahedra; corners with three equivalent O(2)CaU3 tetrahedra; corners with three equivalent O(1)SrU3 tetrahedra; corners with nine O(4,4)Ca3U tetrahedra; edges with three equivalent O(4)Ca3U tetrahedra; and edges with three equivalent O(2)CaU3 tetrahedra. is represented by the CIF card [CIF]
data_SrCaU2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.440
_cell_length_b   12.440
_cell_length_c   12.440
_cell_angle_alpha   18.093
_cell_angle_beta   18.093
_cell_angle_gamma   18.093
_symmetry_Int_Tables_number   1
_cell_volume   162.157
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.500  0.500  0.500  1.0
  U  U2  1  0.752  0.752  0.752  1.0
  U  U3  1  0.248  0.248  0.248  1.0
  O  O4  1  0.072  0.072  0.072  1.0
  O  O5  1  0.567  0.567  0.567  1.0
  O  O6  1  0.928  0.928  0.928  1.0
  O  O7  1  0.433  0.433  0.433  1.0
  O  O8  1  0.698  0.698  0.698  1.0
  O  O9  1  0.194  0.194  0.194  1.0
  O  O10  1  0.302  0.302  0.302  1.0
  O  O11  1  0.806  0.806  0.806  1.0
[/CIF]
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