The material described by CaCu(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Cu(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CuO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cu(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-58°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one Cu(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Cu(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_CaCu(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.711
_cell_length_b   6.711
_cell_length_c   5.284
_cell_angle_alpha   77.910
_cell_angle_beta   77.910
_cell_angle_gamma   84.743
_symmetry_Int_Tables_number   1
_cell_volume   227.247
_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
  Ca  Ca0  1  0.704  0.296  0.750  1.0
  Ca  Ca1  1  0.296  0.704  0.250  1.0
  Cu  Cu2  1  0.906  0.094  0.250  1.0
  Cu  Cu3  1  0.094  0.906  0.750  1.0
  Si  Si4  1  0.380  0.194  0.273  1.0
  Si  Si5  1  0.806  0.620  0.227  1.0
  Si  Si6  1  0.194  0.380  0.773  1.0
  Si  Si7  1  0.620  0.806  0.727  1.0
  O  O8  1  0.369  0.332  0.507  1.0
  O  O9  1  0.668  0.631  0.993  1.0
  O  O10  1  0.631  0.668  0.493  1.0
  O  O11  1  0.332  0.369  0.007  1.0
  O  O12  1  0.609  0.111  0.179  1.0
  O  O13  1  0.889  0.391  0.321  1.0
  O  O14  1  0.391  0.889  0.821  1.0
  O  O15  1  0.111  0.609  0.679  1.0
  O  O16  1  0.027  0.204  0.860  1.0
  O  O17  1  0.796  0.973  0.640  1.0
  O  O18  1  0.204  0.027  0.360  1.0
  O  O19  1  0.973  0.796  0.140  1.0
[/CIF]
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The material described by CaCu(SiO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Cu(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CuO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Cu(1)O6 octahedra. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Cu(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 36-58°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one Cu(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Cu(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_CaCu(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.711
_cell_length_b   6.711
_cell_length_c   5.284
_cell_angle_alpha   77.910
_cell_angle_beta   77.910
_cell_angle_gamma   84.743
_symmetry_Int_Tables_number   1
_cell_volume   227.247
_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
  Ca  Ca0  1  0.704  0.296  0.750  1.0
  Ca  Ca1  1  0.296  0.704  0.250  1.0
  Cu  Cu2  1  0.906  0.094  0.250  1.0
  Cu  Cu3  1  0.094  0.906  0.750  1.0
  Si  Si4  1  0.380  0.194  0.273  1.0
  Si  Si5  1  0.806  0.620  0.227  1.0
  Si  Si6  1  0.194  0.380  0.773  1.0
  Si  Si7  1  0.620  0.806  0.727  1.0
  O  O8  1  0.369  0.332  0.507  1.0
  O  O9  1  0.668  0.631  0.993  1.0
  O  O10  1  0.631  0.668  0.493  1.0
  O  O11  1  0.332  0.369  0.007  1.0
  O  O12  1  0.609  0.111  0.179  1.0
  O  O13  1  0.889  0.391  0.321  1.0
  O  O14  1  0.391  0.889  0.821  1.0
  O  O15  1  0.111  0.609  0.679  1.0
  O  O16  1  0.027  0.204  0.860  1.0
  O  O17  1  0.796  0.973  0.640  1.0
  O  O18  1  0.204  0.027  0.360  1.0
  O  O19  1  0.973  0.796  0.140  1.0
[/CIF]
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