The structure described by CaFeSi2O6 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(1), two equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Fe(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-58°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCaFe2Si trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_CaFe(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.334
_cell_length_b   6.769
_cell_length_c   6.770
_cell_angle_alpha   85.087
_cell_angle_beta   78.733
_cell_angle_gamma   78.733
_symmetry_Int_Tables_number   1
_cell_volume   234.839
_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  0.250  0.298  0.702  1.0
  Ca  Ca1  1  0.750  0.702  0.298  1.0
  Fe  Fe2  1  0.250  0.908  0.092  1.0
  Fe  Fe3  1  0.750  0.092  0.908  1.0
  O  O4  1  0.346  0.211  0.028  1.0
  O  O5  1  0.846  0.028  0.211  1.0
  O  O6  1  0.154  0.972  0.790  1.0
  O  O7  1  0.654  0.790  0.972  1.0
  O  O8  1  0.675  0.119  0.610  1.0
  O  O9  1  0.825  0.390  0.881  1.0
  O  O10  1  0.325  0.881  0.390  1.0
  O  O11  1  0.175  0.610  0.119  1.0
  O  O12  1  0.501  0.634  0.667  1.0
  O  O13  1  0.001  0.667  0.634  1.0
  O  O14  1  0.999  0.333  0.366  1.0
  O  O15  1  0.499  0.366  0.333  1.0
  Si  Si16  1  0.737  0.620  0.804  1.0
  Si  Si17  1  0.237  0.804  0.620  1.0
  Si  Si18  1  0.263  0.380  0.196  1.0
  Si  Si19  1  0.763  0.196  0.380  1.0
[/CIF]
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The structure described by CaFeSi2O6 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(1), two equivalent O(2), and four equivalent O(3) atoms. Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Fe(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 33-58°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), two equivalent Fe(1), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OCaFe2Si trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_CaFe(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.334
_cell_length_b   6.769
_cell_length_c   6.770
_cell_angle_alpha   85.087
_cell_angle_beta   78.733
_cell_angle_gamma   78.733
_symmetry_Int_Tables_number   1
_cell_volume   234.839
_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  0.250  0.298  0.702  1.0
  Ca  Ca1  1  0.750  0.702  0.298  1.0
  Fe  Fe2  1  0.250  0.908  0.092  1.0
  Fe  Fe3  1  0.750  0.092  0.908  1.0
  O  O4  1  0.346  0.211  0.028  1.0
  O  O5  1  0.846  0.028  0.211  1.0
  O  O6  1  0.154  0.972  0.790  1.0
  O  O7  1  0.654  0.790  0.972  1.0
  O  O8  1  0.675  0.119  0.610  1.0
  O  O9  1  0.825  0.390  0.881  1.0
  O  O10  1  0.325  0.881  0.390  1.0
  O  O11  1  0.175  0.610  0.119  1.0
  O  O12  1  0.501  0.634  0.667  1.0
  O  O13  1  0.001  0.667  0.634  1.0
  O  O14  1  0.999  0.333  0.366  1.0
  O  O15  1  0.499  0.366  0.333  1.0
  Si  Si16  1  0.737  0.620  0.804  1.0
  Si  Si17  1  0.237  0.804  0.620  1.0
  Si  Si18  1  0.263  0.380  0.196  1.0
  Si  Si19  1  0.763  0.196  0.380  1.0
[/CIF]
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