The structure described by Ca2SiO4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted single-bond geometry to one O(1) and six equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1) and three equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Ca(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.535
_cell_length_b   5.535
_cell_length_c   7.562
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   200.657
_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  0.667  0.333  0.320  1.0
  Ca  Ca1  1  0.333  0.667  0.820  1.0
  Ca  Ca2  1  0.000  0.000  0.060  1.0
  Ca  Ca3  1  0.000  0.000  0.560  1.0
  Si  Si4  1  0.667  0.333  0.839  1.0
  Si  Si5  1  0.333  0.667  0.339  1.0
  O  O6  1  0.667  0.333  0.053  1.0
  O  O7  1  0.333  0.667  0.553  1.0
  O  O8  1  0.830  0.660  0.775  1.0
  O  O9  1  0.340  0.170  0.775  1.0
  O  O10  1  0.830  0.170  0.775  1.0
  O  O11  1  0.170  0.340  0.275  1.0
  O  O12  1  0.660  0.830  0.275  1.0
  O  O13  1  0.170  0.830  0.275  1.0
[/CIF]
.
The structure described by Ca2SiO4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted single-bond geometry to one O(1) and six equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1) and three equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Ca(1) and one Si(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2SiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.535
_cell_length_b   5.535
_cell_length_c   7.562
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   200.657
_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  0.667  0.333  0.320  1.0
  Ca  Ca1  1  0.333  0.667  0.820  1.0
  Ca  Ca2  1  0.000  0.000  0.060  1.0
  Ca  Ca3  1  0.000  0.000  0.560  1.0
  Si  Si4  1  0.667  0.333  0.839  1.0
  Si  Si5  1  0.333  0.667  0.339  1.0
  O  O6  1  0.667  0.333  0.053  1.0
  O  O7  1  0.333  0.667  0.553  1.0
  O  O8  1  0.830  0.660  0.775  1.0
  O  O9  1  0.340  0.170  0.775  1.0
  O  O10  1  0.830  0.170  0.775  1.0
  O  O11  1  0.170  0.340  0.275  1.0
  O  O12  1  0.660  0.830  0.275  1.0
  O  O13  1  0.170  0.830  0.275  1.0
[/CIF]
.