The compound described by Ca2SiO4 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(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 Ca(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one 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   6.985
_cell_length_b   6.985
_cell_length_c   5.577
_cell_angle_alpha   89.454
_cell_angle_beta   89.454
_cell_angle_gamma   134.814
_symmetry_Int_Tables_number   1
_cell_volume   192.945
_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  0.119  0.988  0.930  1.0
  Ca  Ca1  1  0.252  0.782  0.424  1.0
  Ca  Ca2  1  0.782  0.252  0.924  1.0
  Ca  Ca3  1  0.988  0.119  0.430  1.0
  Si  Si4  1  0.364  0.625  0.923  1.0
  Si  Si5  1  0.625  0.364  0.423  1.0
  O  O6  1  0.173  0.346  0.770  1.0
  O  O7  1  0.685  0.861  0.848  1.0
  O  O8  1  0.222  0.739  0.856  1.0
  O  O9  1  0.298  0.547  0.209  1.0
  O  O10  1  0.739  0.222  0.356  1.0
  O  O11  1  0.346  0.173  0.270  1.0
  O  O12  1  0.547  0.298  0.709  1.0
  O  O13  1  0.861  0.685  0.348  1.0
[/CIF]
.
The compound described by Ca2SiO4 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(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 Ca(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one 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   6.985
_cell_length_b   6.985
_cell_length_c   5.577
_cell_angle_alpha   89.454
_cell_angle_beta   89.454
_cell_angle_gamma   134.814
_symmetry_Int_Tables_number   1
_cell_volume   192.945
_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  0.119  0.988  0.930  1.0
  Ca  Ca1  1  0.252  0.782  0.424  1.0
  Ca  Ca2  1  0.782  0.252  0.924  1.0
  Ca  Ca3  1  0.988  0.119  0.430  1.0
  Si  Si4  1  0.364  0.625  0.923  1.0
  Si  Si5  1  0.625  0.364  0.423  1.0
  O  O6  1  0.173  0.346  0.770  1.0
  O  O7  1  0.685  0.861  0.848  1.0
  O  O8  1  0.222  0.739  0.856  1.0
  O  O9  1  0.298  0.547  0.209  1.0
  O  O10  1  0.739  0.222  0.356  1.0
  O  O11  1  0.346  0.173  0.270  1.0
  O  O12  1  0.547  0.298  0.709  1.0
  O  O13  1  0.861  0.685  0.348  1.0
[/CIF]
.