The crystal structure described by Na4MgCu(AsO4)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NaO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and  an edgeedge with one Na(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-69°. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with four equivalent Na(1)O4 tetrahedra, and edges with two equivalent As(1)O4 tetrahedra. Cu(1) is bonded in a linear geometry to two equivalent O(4) atoms. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with four equivalent Na(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 37°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Mg(1), and one As(1) atom to form distorted ONa2MgAs trigonal pyramids that share corners with three equivalent O(2)Na2MgAs tetrahedra,  a cornercorner with one O(1)Na2MgAs trigonal pyramid, corners with two equivalent O(4)NaMgCuAs trigonal pyramids,  an edgeedge with one O(2)Na2MgAs tetrahedra, and  an edgeedge with one O(4)NaMgCuAs trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Mg(1), and one As(1) atom to form distorted ONa2MgAs tetrahedra that share  a cornercorner with one O(2)Na2MgAs tetrahedra, corners with two equivalent O(4)NaMgCuAs trigonal pyramids, corners with three equivalent O(1)Na2MgAs trigonal pyramids,  an edgeedge with one O(1)Na2MgAs trigonal pyramid, and  an edgeedge with one O(4)NaMgCuAs trigonal pyramid. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Na(2), two equivalent Na(1), and one As(1) atom. In the fourth O site, O(4) is bonded to one Na(2), one Mg(1), one Cu(1), and one As(1) atom to form distorted ONaMgCuAs trigonal pyramids that share corners with two equivalent O(2)Na2MgAs tetrahedra, corners with two equivalent O(1)Na2MgAs trigonal pyramids, corners with two equivalent O(4)NaMgCuAs trigonal pyramids,  an edgeedge with one O(2)Na2MgAs tetrahedra, and  an edgeedge with one O(1)Na2MgAs trigonal pyramid. is represented by the CIF card [CIF]
data_Na4MgCu(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.393
_cell_length_b   6.985
_cell_length_c   6.557
_cell_angle_alpha   87.108
_cell_angle_beta   85.298
_cell_angle_gamma   91.162
_symmetry_Int_Tables_number   1
_cell_volume   245.749
_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
  Na  Na0  1  0.148  0.490  0.217  1.0
  Na  Na1  1  0.852  0.510  0.783  1.0
  Na  Na2  1  0.392  0.264  0.743  1.0
  Na  Na3  1  0.608  0.736  0.257  1.0
  Mg  Mg4  1  0.000  0.000  0.500  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  As  As6  1  0.362  0.759  0.681  1.0
  As  As7  1  0.638  0.241  0.319  1.0
  O  O8  1  0.780  0.251  0.553  1.0
  O  O9  1  0.316  0.217  0.372  1.0
  O  O10  1  0.276  0.562  0.847  1.0
  O  O11  1  0.684  0.783  0.628  1.0
  O  O12  1  0.724  0.438  0.153  1.0
  O  O13  1  0.801  0.027  0.238  1.0
  O  O14  1  0.199  0.973  0.762  1.0
  O  O15  1  0.220  0.749  0.447  1.0
[/CIF]
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The crystal structure described by Na4MgCu(AsO4)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NaO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and  an edgeedge with one Na(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-69°. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with four equivalent Na(1)O4 tetrahedra, and edges with two equivalent As(1)O4 tetrahedra. Cu(1) is bonded in a linear geometry to two equivalent O(4) atoms. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with four equivalent Na(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 37°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Mg(1), and one As(1) atom to form distorted ONa2MgAs trigonal pyramids that share corners with three equivalent O(2)Na2MgAs tetrahedra,  a cornercorner with one O(1)Na2MgAs trigonal pyramid, corners with two equivalent O(4)NaMgCuAs trigonal pyramids,  an edgeedge with one O(2)Na2MgAs tetrahedra, and  an edgeedge with one O(4)NaMgCuAs trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Mg(1), and one As(1) atom to form distorted ONa2MgAs tetrahedra that share  a cornercorner with one O(2)Na2MgAs tetrahedra, corners with two equivalent O(4)NaMgCuAs trigonal pyramids, corners with three equivalent O(1)Na2MgAs trigonal pyramids,  an edgeedge with one O(1)Na2MgAs trigonal pyramid, and  an edgeedge with one O(4)NaMgCuAs trigonal pyramid. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Na(2), two equivalent Na(1), and one As(1) atom. In the fourth O site, O(4) is bonded to one Na(2), one Mg(1), one Cu(1), and one As(1) atom to form distorted ONaMgCuAs trigonal pyramids that share corners with two equivalent O(2)Na2MgAs tetrahedra, corners with two equivalent O(1)Na2MgAs trigonal pyramids, corners with two equivalent O(4)NaMgCuAs trigonal pyramids,  an edgeedge with one O(2)Na2MgAs tetrahedra, and  an edgeedge with one O(1)Na2MgAs trigonal pyramid. is represented by the CIF card [CIF]
data_Na4MgCu(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.393
_cell_length_b   6.985
_cell_length_c   6.557
_cell_angle_alpha   87.108
_cell_angle_beta   85.298
_cell_angle_gamma   91.162
_symmetry_Int_Tables_number   1
_cell_volume   245.749
_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
  Na  Na0  1  0.148  0.490  0.217  1.0
  Na  Na1  1  0.852  0.510  0.783  1.0
  Na  Na2  1  0.392  0.264  0.743  1.0
  Na  Na3  1  0.608  0.736  0.257  1.0
  Mg  Mg4  1  0.000  0.000  0.500  1.0
  Cu  Cu5  1  0.000  0.000  0.000  1.0
  As  As6  1  0.362  0.759  0.681  1.0
  As  As7  1  0.638  0.241  0.319  1.0
  O  O8  1  0.780  0.251  0.553  1.0
  O  O9  1  0.316  0.217  0.372  1.0
  O  O10  1  0.276  0.562  0.847  1.0
  O  O11  1  0.684  0.783  0.628  1.0
  O  O12  1  0.724  0.438  0.153  1.0
  O  O13  1  0.801  0.027  0.238  1.0
  O  O14  1  0.199  0.973  0.762  1.0
  O  O15  1  0.220  0.749  0.447  1.0
[/CIF]
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