The compound described by Na2Mg(NiO2)5 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) 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 Ni(3)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-18°. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with three equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-18°. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Mg(1), one Ni(2), and two equivalent Ni(1) atoms to form ONaMgNi3 square pyramids that share corners with two equivalent O(1)NaMgNi3 square pyramids, corners with three equivalent O(4)NaMgNi3 square pyramids,  a cornercorner with one O(3)NaNi3 trigonal pyramid, corners with three equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid, and edges with two equivalent O(3)NaNi3 trigonal pyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the third O site, O(3) is bonded to one Na(1), one Ni(1), one Ni(2), and one Ni(3) atom to form ONaNi3 trigonal pyramids that share  a cornercorner with one O(1)NaMgNi3 square pyramid, corners with two equivalent O(4)NaMgNi3 square pyramids,  a cornercorner with one O(3)NaNi3 trigonal pyramid, corners with four equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(4)NaMgNi3 square pyramid, and edges with two equivalent O(1)NaMgNi3 square pyramids. In the fourth O site, O(4) is bonded to one Na(1), one Mg(1), one Ni(1), and two equivalent Ni(3) atoms to form ONaMgNi3 square pyramids that share  a cornercorner with one O(4)NaMgNi3 square pyramid, corners with three equivalent O(1)NaMgNi3 square pyramids, corners with two equivalent O(3)NaNi3 trigonal pyramids, corners with two equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(3)NaNi3 trigonal pyramid, and edges with two equivalent O(5)NaNi3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Ni(1), and two equivalent Ni(3) atoms to form ONaNi3 trigonal pyramids that share corners with two equivalent O(4)NaMgNi3 square pyramids, corners with three equivalent O(1)NaMgNi3 square pyramids, corners with four equivalent O(3)NaNi3 trigonal pyramids, edges with two equivalent O(4)NaMgNi3 square pyramids, and  an edgeedge with one O(5)NaNi3 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Mg(NiO2)5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.884
_cell_length_b   4.951
_cell_length_c   6.198
_cell_angle_alpha   78.057
_cell_angle_beta   108.825
_cell_angle_gamma   80.930
_symmetry_Int_Tables_number   1
_cell_volume   189.798
_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  0.908  0.053  0.401  1.0
  Na  Na1  1  0.493  0.748  0.999  1.0
  Mg  Mg2  1  0.200  0.400  0.700  1.0
  Ni  Ni3  1  0.011  0.009  0.982  1.0
  Ni  Ni4  1  0.200  0.400  0.200  1.0
  Ni  Ni5  1  0.389  0.792  0.417  1.0
  Ni  Ni6  1  0.596  0.198  0.610  1.0
  Ni  Ni7  1  0.804  0.603  0.790  1.0
  O  O8  1  0.271  0.109  0.064  1.0
  O  O9  1  0.129  0.691  0.336  1.0
  O  O10  1  0.279  0.128  0.501  1.0
  O  O11  1  0.471  0.463  0.310  1.0
  O  O12  1  0.121  0.672  0.899  1.0
  O  O13  1  0.930  0.337  0.090  1.0
  O  O14  1  0.503  0.487  0.735  1.0
  O  O15  1  0.656  0.878  0.492  1.0
  O  O16  1  0.898  0.313  0.665  1.0
  O  O17  1  0.745  0.922  0.908  1.0
[/CIF]
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The compound described by Na2Mg(NiO2)5 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) 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 Ni(3)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-18°. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with three equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-18°. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NiO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and edges with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Mg(1), one Ni(2), and two equivalent Ni(1) atoms to form ONaMgNi3 square pyramids that share corners with two equivalent O(1)NaMgNi3 square pyramids, corners with three equivalent O(4)NaMgNi3 square pyramids,  a cornercorner with one O(3)NaNi3 trigonal pyramid, corners with three equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid, and edges with two equivalent O(3)NaNi3 trigonal pyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Mg(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the third O site, O(3) is bonded to one Na(1), one Ni(1), one Ni(2), and one Ni(3) atom to form ONaNi3 trigonal pyramids that share  a cornercorner with one O(1)NaMgNi3 square pyramid, corners with two equivalent O(4)NaMgNi3 square pyramids,  a cornercorner with one O(3)NaNi3 trigonal pyramid, corners with four equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(4)NaMgNi3 square pyramid, and edges with two equivalent O(1)NaMgNi3 square pyramids. In the fourth O site, O(4) is bonded to one Na(1), one Mg(1), one Ni(1), and two equivalent Ni(3) atoms to form ONaMgNi3 square pyramids that share  a cornercorner with one O(4)NaMgNi3 square pyramid, corners with three equivalent O(1)NaMgNi3 square pyramids, corners with two equivalent O(3)NaNi3 trigonal pyramids, corners with two equivalent O(5)NaNi3 trigonal pyramids,  an edgeedge with one O(1)NaMgNi3 square pyramid,  an edgeedge with one O(4)NaMgNi3 square pyramid,  an edgeedge with one O(3)NaNi3 trigonal pyramid, and edges with two equivalent O(5)NaNi3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Na(1), one Ni(1), and two equivalent Ni(3) atoms to form ONaNi3 trigonal pyramids that share corners with two equivalent O(4)NaMgNi3 square pyramids, corners with three equivalent O(1)NaMgNi3 square pyramids, corners with four equivalent O(3)NaNi3 trigonal pyramids, edges with two equivalent O(4)NaMgNi3 square pyramids, and  an edgeedge with one O(5)NaNi3 trigonal pyramid. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Mg(NiO2)5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.884
_cell_length_b   4.951
_cell_length_c   6.198
_cell_angle_alpha   78.057
_cell_angle_beta   108.825
_cell_angle_gamma   80.930
_symmetry_Int_Tables_number   1
_cell_volume   189.798
_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  0.908  0.053  0.401  1.0
  Na  Na1  1  0.493  0.748  0.999  1.0
  Mg  Mg2  1  0.200  0.400  0.700  1.0
  Ni  Ni3  1  0.011  0.009  0.982  1.0
  Ni  Ni4  1  0.200  0.400  0.200  1.0
  Ni  Ni5  1  0.389  0.792  0.417  1.0
  Ni  Ni6  1  0.596  0.198  0.610  1.0
  Ni  Ni7  1  0.804  0.603  0.790  1.0
  O  O8  1  0.271  0.109  0.064  1.0
  O  O9  1  0.129  0.691  0.336  1.0
  O  O10  1  0.279  0.128  0.501  1.0
  O  O11  1  0.471  0.463  0.310  1.0
  O  O12  1  0.121  0.672  0.899  1.0
  O  O13  1  0.930  0.337  0.090  1.0
  O  O14  1  0.503  0.487  0.735  1.0
  O  O15  1  0.656  0.878  0.492  1.0
  O  O16  1  0.898  0.313  0.665  1.0
  O  O17  1  0.745  0.922  0.908  1.0
[/CIF]
.