The compound described by Ba2CuP2O9 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(3), one O(7), two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(2), one O(5), two equivalent O(1), two equivalent O(3), two equivalent O(4), and three equivalent O(6) atoms. Cu(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(7) atoms to form distorted CuO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one Cu(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Cu(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to three equivalent Ba(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ba(1) and two equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_Ba2CuP2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   8.490
_cell_length_c   9.047
_cell_angle_alpha   67.796
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.068
_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
  Ba  Ba0  1  0.750  0.791  0.094  1.0
  Ba  Ba1  1  0.250  0.209  0.906  1.0
  Ba  Ba2  1  0.750  0.197  0.282  1.0
  Ba  Ba3  1  0.250  0.803  0.718  1.0
  Cu  Cu4  1  0.500  0.500  0.500  1.0
  Cu  Cu5  1  0.000  0.500  0.500  1.0
  P  P6  1  0.250  0.508  0.187  1.0
  P  P7  1  0.750  0.492  0.813  1.0
  P  P8  1  0.250  0.942  0.303  1.0
  P  P9  1  0.750  0.058  0.697  1.0
  O  O10  1  0.475  0.494  0.291  1.0
  O  O11  1  0.975  0.506  0.709  1.0
  O  O12  1  0.525  0.506  0.709  1.0
  O  O13  1  0.025  0.494  0.291  1.0
  O  O14  1  0.250  0.681  0.049  1.0
  O  O15  1  0.750  0.319  0.951  1.0
  O  O16  1  0.250  0.359  0.132  1.0
  O  O17  1  0.750  0.641  0.868  1.0
  O  O18  1  0.466  0.981  0.195  1.0
  O  O19  1  0.966  0.019  0.805  1.0
  O  O20  1  0.534  0.019  0.805  1.0
  O  O21  1  0.034  0.981  0.195  1.0
  O  O22  1  0.250  0.758  0.432  1.0
  O  O23  1  0.750  0.242  0.568  1.0
  O  O24  1  0.250  0.056  0.403  1.0
  O  O25  1  0.750  0.944  0.597  1.0
  O  O26  1  0.750  0.633  0.435  1.0
  O  O27  1  0.250  0.367  0.565  1.0
[/CIF]
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The compound described by Ba2CuP2O9 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(3), one O(7), two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms. In the second Ba site, Ba(2) is bonded in a 11-coordinate geometry to one O(2), one O(5), two equivalent O(1), two equivalent O(3), two equivalent O(4), and three equivalent O(6) atoms. Cu(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(7) atoms to form distorted CuO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and edges with two equivalent Cu(1)O6 octahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second P site, P(2) is bonded to one O(5), one O(6), and two equivalent O(4) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one Cu(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Cu(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to three equivalent Ba(2) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Ba(1) and two equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_Ba2CuP2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   8.490
_cell_length_c   9.047
_cell_angle_alpha   67.796
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.068
_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
  Ba  Ba0  1  0.750  0.791  0.094  1.0
  Ba  Ba1  1  0.250  0.209  0.906  1.0
  Ba  Ba2  1  0.750  0.197  0.282  1.0
  Ba  Ba3  1  0.250  0.803  0.718  1.0
  Cu  Cu4  1  0.500  0.500  0.500  1.0
  Cu  Cu5  1  0.000  0.500  0.500  1.0
  P  P6  1  0.250  0.508  0.187  1.0
  P  P7  1  0.750  0.492  0.813  1.0
  P  P8  1  0.250  0.942  0.303  1.0
  P  P9  1  0.750  0.058  0.697  1.0
  O  O10  1  0.475  0.494  0.291  1.0
  O  O11  1  0.975  0.506  0.709  1.0
  O  O12  1  0.525  0.506  0.709  1.0
  O  O13  1  0.025  0.494  0.291  1.0
  O  O14  1  0.250  0.681  0.049  1.0
  O  O15  1  0.750  0.319  0.951  1.0
  O  O16  1  0.250  0.359  0.132  1.0
  O  O17  1  0.750  0.641  0.868  1.0
  O  O18  1  0.466  0.981  0.195  1.0
  O  O19  1  0.966  0.019  0.805  1.0
  O  O20  1  0.534  0.019  0.805  1.0
  O  O21  1  0.034  0.981  0.195  1.0
  O  O22  1  0.250  0.758  0.432  1.0
  O  O23  1  0.750  0.242  0.568  1.0
  O  O24  1  0.250  0.056  0.403  1.0
  O  O25  1  0.750  0.944  0.597  1.0
  O  O26  1  0.750  0.633  0.435  1.0
  O  O27  1  0.250  0.367  0.565  1.0
[/CIF]
.