The crystal structure described by MgCu2(PO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form MgO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Cu(2)O5 trigonal bipyramid. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cu(2)O5 trigonal bipyramids and corners with three equivalent Mg(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O5 trigonal bipyramids and corners with three equivalent Cu(2)O5 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(2), and one P(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mg(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(2) atom. is represented by the CIF card [CIF]
data_MgCu2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.901
_cell_length_b   5.331
_cell_length_c   6.378
_cell_angle_alpha   108.177
_cell_angle_beta   86.978
_cell_angle_gamma   111.288
_symmetry_Int_Tables_number   1
_cell_volume   147.180
_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
  Mg  Mg0  1  0.720  0.244  0.689  1.0
  Cu  Cu1  1  0.001  0.001  0.003  1.0
  Cu  Cu2  1  0.280  0.774  0.313  1.0
  P  P3  1  0.359  0.644  0.775  1.0
  P  P4  1  0.640  0.350  0.222  1.0
  O  O5  1  0.387  0.845  0.634  1.0
  O  O6  1  0.614  0.155  0.366  1.0
  O  O7  1  0.667  0.641  0.825  1.0
  O  O8  1  0.333  0.352  0.170  1.0
  O  O9  1  0.235  0.775  0.000  1.0
  O  O10  1  0.765  0.223  1.000  1.0
  O  O11  1  0.153  0.342  0.662  1.0
  O  O12  1  0.847  0.654  0.340  1.0
[/CIF]
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The crystal structure described by MgCu2(PO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(7) atom to form MgO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and  an edgeedge with one Cu(2)O5 trigonal bipyramid. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), one O(5), and one O(6) atom. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Cu(2)O5 trigonal bipyramids and corners with three equivalent Mg(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O5 trigonal bipyramids and corners with three equivalent Cu(2)O5 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cu(2), and one P(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cu(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Cu(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Mg(1) and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Cu(2) and one P(2) atom. is represented by the CIF card [CIF]
data_MgCu2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.901
_cell_length_b   5.331
_cell_length_c   6.378
_cell_angle_alpha   108.177
_cell_angle_beta   86.978
_cell_angle_gamma   111.288
_symmetry_Int_Tables_number   1
_cell_volume   147.180
_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
  Mg  Mg0  1  0.720  0.244  0.689  1.0
  Cu  Cu1  1  0.001  0.001  0.003  1.0
  Cu  Cu2  1  0.280  0.774  0.313  1.0
  P  P3  1  0.359  0.644  0.775  1.0
  P  P4  1  0.640  0.350  0.222  1.0
  O  O5  1  0.387  0.845  0.634  1.0
  O  O6  1  0.614  0.155  0.366  1.0
  O  O7  1  0.667  0.641  0.825  1.0
  O  O8  1  0.333  0.352  0.170  1.0
  O  O9  1  0.235  0.775  0.000  1.0
  O  O10  1  0.765  0.223  1.000  1.0
  O  O11  1  0.153  0.342  0.662  1.0
  O  O12  1  0.847  0.654  0.340  1.0
[/CIF]
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