The compound described by SrMgCu(PO4)2 is Esseneite-derived structured and 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. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share corners with four equivalent Cu(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-85°. Cu(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 CuO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-85°. 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 Mg(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-57°. 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 Cu(1)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, and  an edgeedge with one Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-61°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Mg(1), and one P(1) atom to form distorted edge-sharing OSr2MgP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(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 Cu(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 Mg(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cu(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 trigonal planar geometry to one Mg(1), one Cu(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Cu(1), and one P(2) atom. is represented by the CIF card [CIF]
data_SrMgCu(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.653
_cell_length_b   6.752
_cell_length_c   9.230
_cell_angle_alpha   109.188
_cell_angle_beta   102.233
_cell_angle_gamma   99.406
_symmetry_Int_Tables_number   1
_cell_volume   314.590
_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  0.260  0.804  0.060  1.0
  Sr  Sr1  1  0.740  0.196  0.940  1.0
  Mg  Mg2  1  0.990  0.402  0.648  1.0
  Mg  Mg3  1  0.010  0.598  0.352  1.0
  Cu  Cu4  1  0.643  0.850  0.547  1.0
  Cu  Cu5  1  0.357  0.150  0.453  1.0
  P  P6  1  0.396  0.428  0.242  1.0
  P  P7  1  0.604  0.572  0.758  1.0
  P  P8  1  0.842  0.027  0.301  1.0
  P  P9  1  0.158  0.973  0.699  1.0
  O  O10  1  0.827  0.554  0.880  1.0
  O  O11  1  0.651  0.478  0.209  1.0
  O  O12  1  0.657  0.801  0.750  1.0
  O  O13  1  0.948  0.101  0.681  1.0
  O  O14  1  0.349  0.522  0.791  1.0
  O  O15  1  0.037  0.730  0.588  1.0
  O  O16  1  0.963  0.270  0.412  1.0
  O  O17  1  0.260  0.007  0.875  1.0
  O  O18  1  0.343  0.199  0.250  1.0
  O  O19  1  0.740  0.993  0.125  1.0
  O  O20  1  0.173  0.446  0.120  1.0
  O  O21  1  0.382  0.594  0.404  1.0
  O  O22  1  0.618  0.406  0.596  1.0
  O  O23  1  0.623  0.929  0.356  1.0
  O  O24  1  0.052  0.899  0.319  1.0
  O  O25  1  0.377  0.071  0.644  1.0
[/CIF]
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The compound described by SrMgCu(PO4)2 is Esseneite-derived structured and 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. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share corners with four equivalent Cu(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-85°. Cu(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 CuO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra,  an edgeedge with one Cu(1)O6 octahedra, and  an edgeedge with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-85°. 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 Mg(1)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-57°. 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 Cu(1)O6 octahedra, corners with three equivalent Mg(1)O6 octahedra, and  an edgeedge with one Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-61°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Mg(1), and one P(1) atom to form distorted edge-sharing OSr2MgP trigonal pyramids. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Mg(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 Cu(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 Mg(1), one Cu(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Mg(1), one Cu(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 trigonal planar geometry to one Mg(1), one Cu(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Cu(1), and one P(2) atom. is represented by the CIF card [CIF]
data_SrMgCu(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.653
_cell_length_b   6.752
_cell_length_c   9.230
_cell_angle_alpha   109.188
_cell_angle_beta   102.233
_cell_angle_gamma   99.406
_symmetry_Int_Tables_number   1
_cell_volume   314.590
_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  0.260  0.804  0.060  1.0
  Sr  Sr1  1  0.740  0.196  0.940  1.0
  Mg  Mg2  1  0.990  0.402  0.648  1.0
  Mg  Mg3  1  0.010  0.598  0.352  1.0
  Cu  Cu4  1  0.643  0.850  0.547  1.0
  Cu  Cu5  1  0.357  0.150  0.453  1.0
  P  P6  1  0.396  0.428  0.242  1.0
  P  P7  1  0.604  0.572  0.758  1.0
  P  P8  1  0.842  0.027  0.301  1.0
  P  P9  1  0.158  0.973  0.699  1.0
  O  O10  1  0.827  0.554  0.880  1.0
  O  O11  1  0.651  0.478  0.209  1.0
  O  O12  1  0.657  0.801  0.750  1.0
  O  O13  1  0.948  0.101  0.681  1.0
  O  O14  1  0.349  0.522  0.791  1.0
  O  O15  1  0.037  0.730  0.588  1.0
  O  O16  1  0.963  0.270  0.412  1.0
  O  O17  1  0.260  0.007  0.875  1.0
  O  O18  1  0.343  0.199  0.250  1.0
  O  O19  1  0.740  0.993  0.125  1.0
  O  O20  1  0.173  0.446  0.120  1.0
  O  O21  1  0.382  0.594  0.404  1.0
  O  O22  1  0.618  0.406  0.596  1.0
  O  O23  1  0.623  0.929  0.356  1.0
  O  O24  1  0.052  0.899  0.319  1.0
  O  O25  1  0.377  0.071  0.644  1.0
[/CIF]
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