The compound described by Ca2SiO6 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(4), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(7), and two equivalent O(8) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(11), and two equivalent O(12) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(11), one O(12), one O(4), and one O(5) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3), one O(6), one O(7), and one O(8) atom. There are twelve inequivalent O sites. In the first O site, O(11) is bonded to one Ca(2), two equivalent Ca(4), and one Si(1) atom to form distorted OCa3Si tetrahedra that share  a cornercorner with one O(1)Ca4 tetrahedra, corners with three equivalent O(2)Ca4 tetrahedra,  an edgeedge with one O(11)Ca3Si tetrahedra, and  an edgeedge with one O(1)Ca4 tetrahedra. In the second O site, O(12) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(4), and one Si(1) atom. In the third O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ca(4) atom to form OCa4 tetrahedra that share  a cornercorner with one O(11)Ca3Si tetrahedra, corners with three equivalent O(7)Ca3Si tetrahedra,  an edgeedge with one O(11)Ca3Si tetrahedra, and edges with two equivalent O(2)Ca4 tetrahedra. In the fourth O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ca(4) atom to form OCa4 tetrahedra that share  a cornercorner with one O(7)Ca3Si tetrahedra, corners with three equivalent O(11)Ca3Si tetrahedra,  an edgeedge with one O(7)Ca3Si tetrahedra, and edges with two equivalent O(1)Ca4 tetrahedra. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one Si(2) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ca(2) and one Si(1) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Ca(3) and one Si(1) atom. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(4) and one Si(2) atom. In the ninth O site, O(7) is bonded to one Ca(1), two equivalent Ca(3), and one Si(2) atom to form distorted OCa3Si tetrahedra that share  a cornercorner with one O(2)Ca4 tetrahedra, corners with three equivalent O(1)Ca4 tetrahedra,  an edgeedge with one O(7)Ca3Si tetrahedra, and  an edgeedge with one O(2)Ca4 tetrahedra. In the tenth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(3), and one Si(2) atom. In the eleventh O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1) and one Ca(2) atom. In the twelfth O site, O(10) is bonded in a bent 120 degrees geometry to one Ca(1) and one Ca(2) atom. is represented by the CIF file [CIF]
data_Ca2SiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.699
_cell_length_b   8.439
_cell_length_c   10.868
_cell_angle_alpha   90.170
_cell_angle_beta   91.222
_cell_angle_gamma   96.605
_symmetry_Int_Tables_number   1
_cell_volume   519.083
_cell_formula_units_Z   4
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  0.781  0.819  0.117  1.0
  Ca  Ca1  1  0.219  0.181  0.883  1.0
  Ca  Ca2  1  0.296  0.815  0.387  1.0
  Ca  Ca3  1  0.704  0.185  0.613  1.0
  Ca  Ca4  1  0.259  0.480  0.127  1.0
  Ca  Ca5  1  0.741  0.520  0.873  1.0
  Ca  Ca6  1  0.761  0.479  0.370  1.0
  Ca  Ca7  1  0.239  0.521  0.630  1.0
  Si  Si8  1  0.201  0.243  0.430  1.0
  Si  Si9  1  0.799  0.757  0.570  1.0
  Si  Si10  1  0.723  0.245  0.064  1.0
  Si  Si11  1  0.277  0.755  0.936  1.0
  O  O12  1  0.039  0.658  0.239  1.0
  O  O13  1  0.961  0.342  0.761  1.0
  O  O14  1  0.536  0.654  0.257  1.0
  O  O15  1  0.464  0.346  0.743  1.0
  O  O16  1  0.703  0.054  0.021  1.0
  O  O17  1  0.297  0.946  0.979  1.0
  O  O18  1  0.191  0.052  0.469  1.0
  O  O19  1  0.809  0.948  0.531  1.0
  O  O20  1  0.193  0.283  0.281  1.0
  O  O21  1  0.807  0.717  0.719  1.0
  O  O22  1  0.758  0.286  0.212  1.0
  O  O23  1  0.242  0.714  0.788  1.0
  O  O24  1  0.500  0.330  0.012  1.0
  O  O25  1  0.500  0.670  0.988  1.0
  O  O26  1  0.969  0.329  0.001  1.0
  O  O27  1  0.031  0.671  0.999  1.0
  O  O28  1  0.171  0.919  0.188  1.0
  O  O29  1  0.829  0.081  0.812  1.0
  O  O30  1  0.660  0.913  0.307  1.0
  O  O31  1  0.340  0.087  0.693  1.0
  O  O32  1  0.005  0.671  0.502  1.0
  O  O33  1  0.995  0.329  0.498  1.0
  O  O34  1  0.464  0.324  0.476  1.0
  O  O35  1  0.536  0.676  0.524  1.0
[/CIF]
.
The compound described by Ca2SiO6 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(7), one O(8), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(4), and one O(9) atom. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(7), and two equivalent O(8) atoms. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(6), two equivalent O(11), and two equivalent O(12) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a tetrahedral geometry to one O(11), one O(12), one O(4), and one O(5) atom. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(3), one O(6), one O(7), and one O(8) atom. There are twelve inequivalent O sites. In the first O site, O(11) is bonded to one Ca(2), two equivalent Ca(4), and one Si(1) atom to form distorted OCa3Si tetrahedra that share  a cornercorner with one O(1)Ca4 tetrahedra, corners with three equivalent O(2)Ca4 tetrahedra,  an edgeedge with one O(11)Ca3Si tetrahedra, and  an edgeedge with one O(1)Ca4 tetrahedra. In the second O site, O(12) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(4), and one Si(1) atom. In the third O site, O(1) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ca(4) atom to form OCa4 tetrahedra that share  a cornercorner with one O(11)Ca3Si tetrahedra, corners with three equivalent O(7)Ca3Si tetrahedra,  an edgeedge with one O(11)Ca3Si tetrahedra, and edges with two equivalent O(2)Ca4 tetrahedra. In the fourth O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(3), and one Ca(4) atom to form OCa4 tetrahedra that share  a cornercorner with one O(7)Ca3Si tetrahedra, corners with three equivalent O(11)Ca3Si tetrahedra,  an edgeedge with one O(7)Ca3Si tetrahedra, and edges with two equivalent O(1)Ca4 tetrahedra. In the fifth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one Si(2) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ca(2) and one Si(1) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Ca(3) and one Si(1) atom. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(4) and one Si(2) atom. In the ninth O site, O(7) is bonded to one Ca(1), two equivalent Ca(3), and one Si(2) atom to form distorted OCa3Si tetrahedra that share  a cornercorner with one O(2)Ca4 tetrahedra, corners with three equivalent O(1)Ca4 tetrahedra,  an edgeedge with one O(7)Ca3Si tetrahedra, and  an edgeedge with one O(2)Ca4 tetrahedra. In the tenth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(3), and one Si(2) atom. In the eleventh O site, O(9) is bonded in a bent 120 degrees geometry to one Ca(1) and one Ca(2) atom. In the twelfth O site, O(10) is bonded in a bent 120 degrees geometry to one Ca(1) and one Ca(2) atom. is represented by the CIF file [CIF]
data_Ca2SiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.699
_cell_length_b   8.439
_cell_length_c   10.868
_cell_angle_alpha   90.170
_cell_angle_beta   91.222
_cell_angle_gamma   96.605
_symmetry_Int_Tables_number   1
_cell_volume   519.083
_cell_formula_units_Z   4
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  0.781  0.819  0.117  1.0
  Ca  Ca1  1  0.219  0.181  0.883  1.0
  Ca  Ca2  1  0.296  0.815  0.387  1.0
  Ca  Ca3  1  0.704  0.185  0.613  1.0
  Ca  Ca4  1  0.259  0.480  0.127  1.0
  Ca  Ca5  1  0.741  0.520  0.873  1.0
  Ca  Ca6  1  0.761  0.479  0.370  1.0
  Ca  Ca7  1  0.239  0.521  0.630  1.0
  Si  Si8  1  0.201  0.243  0.430  1.0
  Si  Si9  1  0.799  0.757  0.570  1.0
  Si  Si10  1  0.723  0.245  0.064  1.0
  Si  Si11  1  0.277  0.755  0.936  1.0
  O  O12  1  0.039  0.658  0.239  1.0
  O  O13  1  0.961  0.342  0.761  1.0
  O  O14  1  0.536  0.654  0.257  1.0
  O  O15  1  0.464  0.346  0.743  1.0
  O  O16  1  0.703  0.054  0.021  1.0
  O  O17  1  0.297  0.946  0.979  1.0
  O  O18  1  0.191  0.052  0.469  1.0
  O  O19  1  0.809  0.948  0.531  1.0
  O  O20  1  0.193  0.283  0.281  1.0
  O  O21  1  0.807  0.717  0.719  1.0
  O  O22  1  0.758  0.286  0.212  1.0
  O  O23  1  0.242  0.714  0.788  1.0
  O  O24  1  0.500  0.330  0.012  1.0
  O  O25  1  0.500  0.670  0.988  1.0
  O  O26  1  0.969  0.329  0.001  1.0
  O  O27  1  0.031  0.671  0.999  1.0
  O  O28  1  0.171  0.919  0.188  1.0
  O  O29  1  0.829  0.081  0.812  1.0
  O  O30  1  0.660  0.913  0.307  1.0
  O  O31  1  0.340  0.087  0.693  1.0
  O  O32  1  0.005  0.671  0.502  1.0
  O  O33  1  0.995  0.329  0.498  1.0
  O  O34  1  0.464  0.324  0.476  1.0
  O  O35  1  0.536  0.676  0.524  1.0
[/CIF]
.