The material described by Co2Si(P2O7)2 crystallizes in the monoclinic C2/c space group. Co(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(7) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. Si(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-57°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-63°. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the second O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one P(2) atom. In the fifth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the sixth O site, O(7) is bonded in a trigonal planar geometry to two equivalent Co(1) and one P(2) atom. In the seventh O site, O(1) is bonded in a linear geometry to one Si(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Co2Si(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.914
_cell_length_b   8.914
_cell_length_c   12.423
_cell_angle_alpha   77.473
_cell_angle_beta   77.473
_cell_angle_gamma   32.737
_symmetry_Int_Tables_number   1
_cell_volume   519.989
_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
  Co  Co0  1  0.904  0.602  0.130  1.0
  Co  Co1  1  0.398  0.096  0.370  1.0
  Co  Co2  1  0.096  0.398  0.870  1.0
  Co  Co3  1  0.602  0.904  0.630  1.0
  Si  Si4  1  0.849  0.151  0.250  1.0
  Si  Si5  1  0.151  0.849  0.750  1.0
  P  P6  1  0.302  0.969  0.085  1.0
  P  P7  1  0.031  0.698  0.415  1.0
  P  P8  1  0.513  0.235  0.136  1.0
  P  P9  1  0.765  0.487  0.364  1.0
  P  P10  1  0.487  0.765  0.864  1.0
  P  P11  1  0.235  0.513  0.636  1.0
  P  P12  1  0.698  0.031  0.915  1.0
  P  P13  1  0.969  0.302  0.585  1.0
  O  O14  1  0.898  0.976  0.832  1.0
  O  O15  1  0.024  0.102  0.668  1.0
  O  O16  1  0.102  0.024  0.168  1.0
  O  O17  1  0.976  0.898  0.332  1.0
  O  O18  1  0.832  0.763  0.953  1.0
  O  O19  1  0.237  0.168  0.547  1.0
  O  O20  1  0.168  0.237  0.047  1.0
  O  O21  1  0.763  0.832  0.453  1.0
  O  O22  1  0.582  0.729  0.131  1.0
  O  O23  1  0.271  0.418  0.369  1.0
  O  O24  1  0.418  0.271  0.869  1.0
  O  O25  1  0.729  0.582  0.631  1.0
  O  O26  1  0.687  0.125  0.017  1.0
  O  O27  1  0.875  0.313  0.483  1.0
  O  O28  1  0.297  0.612  0.679  1.0
  O  O29  1  0.388  0.703  0.821  1.0
  O  O30  1  0.703  0.388  0.321  1.0
  O  O31  1  0.612  0.297  0.179  1.0
  O  O32  1  0.505  0.207  0.621  1.0
  O  O33  1  0.793  0.495  0.879  1.0
  O  O34  1  0.495  0.793  0.379  1.0
  O  O35  1  0.207  0.505  0.121  1.0
  O  O36  1  0.383  0.003  0.796  1.0
  O  O37  1  0.997  0.617  0.704  1.0
  O  O38  1  0.617  0.997  0.204  1.0
  O  O39  1  0.003  0.383  0.296  1.0
  O  O40  1  0.125  0.687  0.517  1.0
  O  O41  1  0.313  0.875  0.983  1.0
[/CIF]
.
The material described by Co2Si(P2O7)2 crystallizes in the monoclinic C2/c space group. Co(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(7) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. Si(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 42-57°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-63°. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the second O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(4) is bonded in a bent 120 degrees geometry to one P(1) and one P(2) atom. In the fourth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one P(2) atom. In the fifth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. In the sixth O site, O(7) is bonded in a trigonal planar geometry to two equivalent Co(1) and one P(2) atom. In the seventh O site, O(1) is bonded in a linear geometry to one Si(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Co2Si(P2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.914
_cell_length_b   8.914
_cell_length_c   12.423
_cell_angle_alpha   77.473
_cell_angle_beta   77.473
_cell_angle_gamma   32.737
_symmetry_Int_Tables_number   1
_cell_volume   519.989
_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
  Co  Co0  1  0.904  0.602  0.130  1.0
  Co  Co1  1  0.398  0.096  0.370  1.0
  Co  Co2  1  0.096  0.398  0.870  1.0
  Co  Co3  1  0.602  0.904  0.630  1.0
  Si  Si4  1  0.849  0.151  0.250  1.0
  Si  Si5  1  0.151  0.849  0.750  1.0
  P  P6  1  0.302  0.969  0.085  1.0
  P  P7  1  0.031  0.698  0.415  1.0
  P  P8  1  0.513  0.235  0.136  1.0
  P  P9  1  0.765  0.487  0.364  1.0
  P  P10  1  0.487  0.765  0.864  1.0
  P  P11  1  0.235  0.513  0.636  1.0
  P  P12  1  0.698  0.031  0.915  1.0
  P  P13  1  0.969  0.302  0.585  1.0
  O  O14  1  0.898  0.976  0.832  1.0
  O  O15  1  0.024  0.102  0.668  1.0
  O  O16  1  0.102  0.024  0.168  1.0
  O  O17  1  0.976  0.898  0.332  1.0
  O  O18  1  0.832  0.763  0.953  1.0
  O  O19  1  0.237  0.168  0.547  1.0
  O  O20  1  0.168  0.237  0.047  1.0
  O  O21  1  0.763  0.832  0.453  1.0
  O  O22  1  0.582  0.729  0.131  1.0
  O  O23  1  0.271  0.418  0.369  1.0
  O  O24  1  0.418  0.271  0.869  1.0
  O  O25  1  0.729  0.582  0.631  1.0
  O  O26  1  0.687  0.125  0.017  1.0
  O  O27  1  0.875  0.313  0.483  1.0
  O  O28  1  0.297  0.612  0.679  1.0
  O  O29  1  0.388  0.703  0.821  1.0
  O  O30  1  0.703  0.388  0.321  1.0
  O  O31  1  0.612  0.297  0.179  1.0
  O  O32  1  0.505  0.207  0.621  1.0
  O  O33  1  0.793  0.495  0.879  1.0
  O  O34  1  0.495  0.793  0.379  1.0
  O  O35  1  0.207  0.505  0.121  1.0
  O  O36  1  0.383  0.003  0.796  1.0
  O  O37  1  0.997  0.617  0.704  1.0
  O  O38  1  0.617  0.997  0.204  1.0
  O  O39  1  0.003  0.383  0.296  1.0
  O  O40  1  0.125  0.687  0.517  1.0
  O  O41  1  0.313  0.875  0.983  1.0
[/CIF]
.