The structure described by SrCaNi(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-80°. Ni(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted NiO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-80°. 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(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-60°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Ca(1), and one P(1) atom to form distorted edge-sharing OSr2CaP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Ca(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ni(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 distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Ni(1), and one P(2) atom. is represented by the CIF file [CIF]
data_SrCaNi(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.720
_cell_length_b   6.928
_cell_length_c   9.448
_cell_angle_alpha   109.409
_cell_angle_beta   101.902
_cell_angle_gamma   98.524
_symmetry_Int_Tables_number   1
_cell_volume   335.882
_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
  Sr  Sr0  1  0.263  0.808  0.060  1.0
  Sr  Sr1  1  0.737  0.192  0.940  1.0
  Ca  Ca2  1  0.996  0.419  0.661  1.0
  Ca  Ca3  1  0.004  0.581  0.339  1.0
  Ni  Ni4  1  0.653  0.850  0.560  1.0
  Ni  Ni5  1  0.347  0.150  0.440  1.0
  P  P6  1  0.396  0.417  0.228  1.0
  P  P7  1  0.604  0.583  0.772  1.0
  P  P8  1  0.841  0.031  0.300  1.0
  P  P9  1  0.159  0.969  0.700  1.0
  O  O10  1  0.838  0.560  0.879  1.0
  O  O11  1  0.624  0.451  0.168  1.0
  O  O12  1  0.652  0.801  0.759  1.0
  O  O13  1  0.959  0.103  0.696  1.0
  O  O14  1  0.376  0.549  0.832  1.0
  O  O15  1  0.007  0.738  0.594  1.0
  O  O16  1  0.993  0.262  0.406  1.0
  O  O17  1  0.274  0.997  0.869  1.0
  O  O18  1  0.348  0.199  0.241  1.0
  O  O19  1  0.726  0.003  0.131  1.0
  O  O20  1  0.162  0.440  0.121  1.0
  O  O21  1  0.426  0.590  0.392  1.0
  O  O22  1  0.574  0.410  0.608  1.0
  O  O23  1  0.638  0.967  0.376  1.0
  O  O24  1  0.041  0.897  0.304  1.0
  O  O25  1  0.362  0.033  0.624  1.0
[/CIF]
.
The structure described by SrCaNi(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form CaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-80°. Ni(1) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms to form distorted NiO6 octahedra that share corners with four equivalent Ca(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 60-80°. 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(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-60°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Ca(1), and one P(1) atom to form distorted edge-sharing OSr2CaP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Ca(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ni(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 distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ca(1), one Ni(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Ni(1), and one P(2) atom. is represented by the CIF file [CIF]
data_SrCaNi(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.720
_cell_length_b   6.928
_cell_length_c   9.448
_cell_angle_alpha   109.409
_cell_angle_beta   101.902
_cell_angle_gamma   98.524
_symmetry_Int_Tables_number   1
_cell_volume   335.882
_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
  Sr  Sr0  1  0.263  0.808  0.060  1.0
  Sr  Sr1  1  0.737  0.192  0.940  1.0
  Ca  Ca2  1  0.996  0.419  0.661  1.0
  Ca  Ca3  1  0.004  0.581  0.339  1.0
  Ni  Ni4  1  0.653  0.850  0.560  1.0
  Ni  Ni5  1  0.347  0.150  0.440  1.0
  P  P6  1  0.396  0.417  0.228  1.0
  P  P7  1  0.604  0.583  0.772  1.0
  P  P8  1  0.841  0.031  0.300  1.0
  P  P9  1  0.159  0.969  0.700  1.0
  O  O10  1  0.838  0.560  0.879  1.0
  O  O11  1  0.624  0.451  0.168  1.0
  O  O12  1  0.652  0.801  0.759  1.0
  O  O13  1  0.959  0.103  0.696  1.0
  O  O14  1  0.376  0.549  0.832  1.0
  O  O15  1  0.007  0.738  0.594  1.0
  O  O16  1  0.993  0.262  0.406  1.0
  O  O17  1  0.274  0.997  0.869  1.0
  O  O18  1  0.348  0.199  0.241  1.0
  O  O19  1  0.726  0.003  0.131  1.0
  O  O20  1  0.162  0.440  0.121  1.0
  O  O21  1  0.426  0.590  0.392  1.0
  O  O22  1  0.574  0.410  0.608  1.0
  O  O23  1  0.638  0.967  0.376  1.0
  O  O24  1  0.041  0.897  0.304  1.0
  O  O25  1  0.362  0.033  0.624  1.0
[/CIF]
.