The crystal structure described by KCa2(P2O9)2 crystallizes in the triclinic P1 space group. K(1) is bonded to one O(13), one O(17), one O(18), one O(3), and one O(4) atom to form distorted KO5 trigonal bipyramids that share corners with two equivalent P(4)O4 tetrahedra and corners with three equivalent P(3)O4 tetrahedra. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(12), one O(16), one O(2), one O(6), one O(7), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(15), one O(2), one O(5), one O(8), and one O(9) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(1), one O(11), one O(15), and one O(9) atom. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(10), one O(12), one O(16), and one O(2) atom. In the third P site, P(3) is bonded to one O(13), one O(17), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent K(1)O5 trigonal bipyramids. In the fourth P site, P(4) is bonded to one O(14), one O(18), one O(4), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent K(1)O5 trigonal bipyramids. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1) and one P(4) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ca(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one Ca(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Ca(2) and one P(1) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Ca(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one K(1) and one P(3) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one P(4) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one Ca(2) and one P(1) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one Ca(1) and one P(2) atom. In the seventeenth O site, O(17) is bonded in a distorted single-bond geometry to one K(1) and one P(3) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one K(1) and one P(4) atom. is represented by the CIF file [CIF]
data_KCa2(P2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.643
_cell_length_b   6.149
_cell_length_c   12.872
_cell_angle_alpha   101.966
_cell_angle_beta   85.089
_cell_angle_gamma   114.485
_symmetry_Int_Tables_number   1
_cell_volume   397.618
_cell_formula_units_Z   1
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
  K  K0  1  0.501  0.964  0.531  1.0
  Ca  Ca1  1  0.003  0.294  0.097  1.0
  Ca  Ca2  1  0.994  0.705  0.903  1.0
  P  P3  1  0.503  0.209  0.900  1.0
  P  P4  1  0.495  0.791  0.100  1.0
  P  P5  1  0.148  0.382  0.646  1.0
  P  P6  1  0.856  0.621  0.356  1.0
  O  O7  1  0.247  0.147  0.963  1.0
  O  O8  1  0.752  0.851  0.037  1.0
  O  O9  1  0.126  0.119  0.607  1.0
  O  O10  1  0.864  0.880  0.393  1.0
  O  O11  1  0.106  0.441  0.766  1.0
  O  O12  1  0.896  0.560  0.236  1.0
  O  O13  1  0.159  0.153  0.252  1.0
  O  O14  1  0.844  0.850  0.747  1.0
  O  O15  1  0.745  0.313  0.971  1.0
  O  O16  1  0.254  0.685  0.028  1.0
  O  O17  1  0.544  0.398  0.829  1.0
  O  O18  1  0.456  0.604  0.172  1.0
  O  O19  1  0.419  0.548  0.610  1.0
  O  O20  1  0.586  0.453  0.392  1.0
  O  O21  1  0.473  0.971  0.819  1.0
  O  O22  1  0.526  0.033  0.178  1.0
  O  O23  1  0.925  0.417  0.599  1.0
  O  O24  1  0.077  0.598  0.408  1.0
[/CIF]
.
The crystal structure described by KCa2(P2O9)2 crystallizes in the triclinic P1 space group. K(1) is bonded to one O(13), one O(17), one O(18), one O(3), and one O(4) atom to form distorted KO5 trigonal bipyramids that share corners with two equivalent P(4)O4 tetrahedra and corners with three equivalent P(3)O4 tetrahedra. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(12), one O(16), one O(2), one O(6), one O(7), and one O(9) atom. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(15), one O(2), one O(5), one O(8), and one O(9) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(1), one O(11), one O(15), and one O(9) atom. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(10), one O(12), one O(16), and one O(2) atom. In the third P site, P(3) is bonded to one O(13), one O(17), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent K(1)O5 trigonal bipyramids. In the fourth P site, P(4) is bonded to one O(14), one O(18), one O(4), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent K(1)O5 trigonal bipyramids. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(1) and one P(4) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ca(2) and one P(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Ca(1) and one P(4) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. In the eighth O site, O(8) is bonded in a single-bond geometry to one Ca(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Ca(1), one Ca(2), and one P(2) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Ca(2) and one P(1) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one Ca(1) and one P(2) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to one K(1) and one P(3) atom. In the fourteenth O site, O(14) is bonded in a single-bond geometry to one P(4) atom. In the fifteenth O site, O(15) is bonded in a single-bond geometry to one Ca(2) and one P(1) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one Ca(1) and one P(2) atom. In the seventeenth O site, O(17) is bonded in a distorted single-bond geometry to one K(1) and one P(3) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one K(1) and one P(4) atom. is represented by the CIF file [CIF]
data_KCa2(P2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.643
_cell_length_b   6.149
_cell_length_c   12.872
_cell_angle_alpha   101.966
_cell_angle_beta   85.089
_cell_angle_gamma   114.485
_symmetry_Int_Tables_number   1
_cell_volume   397.618
_cell_formula_units_Z   1
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
  K  K0  1  0.501  0.964  0.531  1.0
  Ca  Ca1  1  0.003  0.294  0.097  1.0
  Ca  Ca2  1  0.994  0.705  0.903  1.0
  P  P3  1  0.503  0.209  0.900  1.0
  P  P4  1  0.495  0.791  0.100  1.0
  P  P5  1  0.148  0.382  0.646  1.0
  P  P6  1  0.856  0.621  0.356  1.0
  O  O7  1  0.247  0.147  0.963  1.0
  O  O8  1  0.752  0.851  0.037  1.0
  O  O9  1  0.126  0.119  0.607  1.0
  O  O10  1  0.864  0.880  0.393  1.0
  O  O11  1  0.106  0.441  0.766  1.0
  O  O12  1  0.896  0.560  0.236  1.0
  O  O13  1  0.159  0.153  0.252  1.0
  O  O14  1  0.844  0.850  0.747  1.0
  O  O15  1  0.745  0.313  0.971  1.0
  O  O16  1  0.254  0.685  0.028  1.0
  O  O17  1  0.544  0.398  0.829  1.0
  O  O18  1  0.456  0.604  0.172  1.0
  O  O19  1  0.419  0.548  0.610  1.0
  O  O20  1  0.586  0.453  0.392  1.0
  O  O21  1  0.473  0.971  0.819  1.0
  O  O22  1  0.526  0.033  0.178  1.0
  O  O23  1  0.925  0.417  0.599  1.0
  O  O24  1  0.077  0.598  0.408  1.0
[/CIF]
.