The crystal structure described by CaNiP2O7 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(7), two equivalent O(4), and two equivalent O(5) atoms. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form NiO5 square pyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)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(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O5 square pyramids and  a cornercorner with one P(2)O4 tetrahedra. 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 two equivalent Ni(1)O5 square pyramids and  a cornercorner with one P(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ni(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ni(1), and one P(2) atom. is represented by the CIF card [CIF]
data_CaNiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.313
_cell_length_b   6.556
_cell_length_c   7.019
_cell_angle_alpha   83.255
_cell_angle_beta   89.764
_cell_angle_gamma   68.195
_symmetry_Int_Tables_number   1
_cell_volume   267.619
_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  0.297  0.727  0.624  1.0
  Ca  Ca1  1  0.703  0.273  0.376  1.0
  Ni  Ni2  1  0.752  0.872  0.804  1.0
  Ni  Ni3  1  0.248  0.128  0.196  1.0
  P  P4  1  0.162  0.659  0.121  1.0
  P  P5  1  0.838  0.341  0.879  1.0
  P  P6  1  0.247  0.220  0.627  1.0
  P  P7  1  0.753  0.780  0.373  1.0
  O  O8  1  0.080  0.747  0.910  1.0
  O  O9  1  0.920  0.253  0.090  1.0
  O  O10  1  0.243  0.811  0.222  1.0
  O  O11  1  0.757  0.189  0.778  1.0
  O  O12  1  0.326  0.416  0.144  1.0
  O  O13  1  0.674  0.584  0.856  1.0
  O  O14  1  0.643  0.621  0.451  1.0
  O  O15  1  0.357  0.379  0.549  1.0
  O  O16  1  0.120  0.155  0.469  1.0
  O  O17  1  0.880  0.845  0.531  1.0
  O  O18  1  0.067  0.348  0.773  1.0
  O  O19  1  0.933  0.652  0.227  1.0
  O  O20  1  0.588  0.998  0.261  1.0
  O  O21  1  0.412  0.002  0.739  1.0
[/CIF]
.
The crystal structure described by CaNiP2O7 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(3), one O(7), two equivalent O(4), and two equivalent O(5) atoms. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form NiO5 square pyramids that share corners with two equivalent P(2)O4 tetrahedra and corners with three equivalent P(1)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(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O5 square pyramids and  a cornercorner with one P(2)O4 tetrahedra. 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 two equivalent Ni(1)O5 square pyramids and  a cornercorner with one P(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ca(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ni(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ni(1), and one P(2) atom. is represented by the CIF card [CIF]
data_CaNiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.313
_cell_length_b   6.556
_cell_length_c   7.019
_cell_angle_alpha   83.255
_cell_angle_beta   89.764
_cell_angle_gamma   68.195
_symmetry_Int_Tables_number   1
_cell_volume   267.619
_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  0.297  0.727  0.624  1.0
  Ca  Ca1  1  0.703  0.273  0.376  1.0
  Ni  Ni2  1  0.752  0.872  0.804  1.0
  Ni  Ni3  1  0.248  0.128  0.196  1.0
  P  P4  1  0.162  0.659  0.121  1.0
  P  P5  1  0.838  0.341  0.879  1.0
  P  P6  1  0.247  0.220  0.627  1.0
  P  P7  1  0.753  0.780  0.373  1.0
  O  O8  1  0.080  0.747  0.910  1.0
  O  O9  1  0.920  0.253  0.090  1.0
  O  O10  1  0.243  0.811  0.222  1.0
  O  O11  1  0.757  0.189  0.778  1.0
  O  O12  1  0.326  0.416  0.144  1.0
  O  O13  1  0.674  0.584  0.856  1.0
  O  O14  1  0.643  0.621  0.451  1.0
  O  O15  1  0.357  0.379  0.549  1.0
  O  O16  1  0.120  0.155  0.469  1.0
  O  O17  1  0.880  0.845  0.531  1.0
  O  O18  1  0.067  0.348  0.773  1.0
  O  O19  1  0.933  0.652  0.227  1.0
  O  O20  1  0.588  0.998  0.261  1.0
  O  O21  1  0.412  0.002  0.739  1.0
[/CIF]
.