The crystal structure described by MgNb4(NO)4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a distorted hexagonal planar geometry to two equivalent N(1) and four equivalent O(2) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one N(2), two equivalent N(1), one O(2), and two equivalent O(1) atoms to form distorted NbN3O3 pentagonal pyramids that share corners with two equivalent Nb(2)N4O2 octahedra, corners with two equivalent Nb(1)N3O3 pentagonal pyramids, edges with three equivalent Nb(2)N4O2 octahedra, and  an edgeedge with one Nb(1)N3O3 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 35-41°. In the second Nb site, Nb(2) is bonded to one N(1), three equivalent N(2), one O(1), and one O(2) atom to form distorted NbN4O2 octahedra that share corners with two equivalent Nb(2)N4O2 octahedra, corners with two equivalent Nb(1)N3O3 pentagonal pyramids, edges with two equivalent Nb(2)N4O2 octahedra, and edges with three equivalent Nb(1)N3O3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 21°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted square co-planar geometry to one Mg(1), one Nb(2), and two equivalent Nb(1) atoms. In the second N site, N(2) is bonded to one Nb(1) and three equivalent Nb(2) atoms to form distorted NNb4 trigonal pyramids that share corners with four equivalent O(2)Mg2Nb2 tetrahedra, corners with two equivalent N(2)Nb4 trigonal pyramids, and edges with two equivalent N(2)Nb4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Nb(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Nb(1), and one Nb(2) atom to form distorted OMg2Nb2 tetrahedra that share corners with four equivalent O(2)Mg2Nb2 tetrahedra, corners with four equivalent N(2)Nb4 trigonal pyramids, and  an edgeedge with one O(2)Mg2Nb2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb4(NO)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.057
_cell_length_b   6.457
_cell_length_c   6.748
_cell_angle_alpha   75.988
_cell_angle_beta   90.000
_cell_angle_gamma   71.690
_symmetry_Int_Tables_number   1
_cell_volume   162.278
_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  0.500  0.000  0.000  1.0
  Nb  Nb1  1  0.106  0.788  0.710  1.0
  Nb  Nb2  1  0.220  0.559  0.297  1.0
  Nb  Nb3  1  0.780  0.441  0.703  1.0
  Nb  Nb4  1  0.894  0.212  0.290  1.0
  N  N5  1  0.623  0.754  0.778  1.0
  N  N6  1  0.267  0.466  0.645  1.0
  N  N7  1  0.733  0.534  0.355  1.0
  N  N8  1  0.377  0.246  0.222  1.0
  O  O9  1  0.063  0.873  0.390  1.0
  O  O10  1  0.110  0.781  0.031  1.0
  O  O11  1  0.890  0.219  0.969  1.0
  O  O12  1  0.937  0.127  0.610  1.0
[/CIF]
.
The crystal structure described by MgNb4(NO)4 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a distorted hexagonal planar geometry to two equivalent N(1) and four equivalent O(2) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one N(2), two equivalent N(1), one O(2), and two equivalent O(1) atoms to form distorted NbN3O3 pentagonal pyramids that share corners with two equivalent Nb(2)N4O2 octahedra, corners with two equivalent Nb(1)N3O3 pentagonal pyramids, edges with three equivalent Nb(2)N4O2 octahedra, and  an edgeedge with one Nb(1)N3O3 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 35-41°. In the second Nb site, Nb(2) is bonded to one N(1), three equivalent N(2), one O(1), and one O(2) atom to form distorted NbN4O2 octahedra that share corners with two equivalent Nb(2)N4O2 octahedra, corners with two equivalent Nb(1)N3O3 pentagonal pyramids, edges with two equivalent Nb(2)N4O2 octahedra, and edges with three equivalent Nb(1)N3O3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 21°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted square co-planar geometry to one Mg(1), one Nb(2), and two equivalent Nb(1) atoms. In the second N site, N(2) is bonded to one Nb(1) and three equivalent Nb(2) atoms to form distorted NNb4 trigonal pyramids that share corners with four equivalent O(2)Mg2Nb2 tetrahedra, corners with two equivalent N(2)Nb4 trigonal pyramids, and edges with two equivalent N(2)Nb4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Nb(2) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Nb(1), and one Nb(2) atom to form distorted OMg2Nb2 tetrahedra that share corners with four equivalent O(2)Mg2Nb2 tetrahedra, corners with four equivalent N(2)Nb4 trigonal pyramids, and  an edgeedge with one O(2)Mg2Nb2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb4(NO)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.057
_cell_length_b   6.457
_cell_length_c   6.748
_cell_angle_alpha   75.988
_cell_angle_beta   90.000
_cell_angle_gamma   71.690
_symmetry_Int_Tables_number   1
_cell_volume   162.278
_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  0.500  0.000  0.000  1.0
  Nb  Nb1  1  0.106  0.788  0.710  1.0
  Nb  Nb2  1  0.220  0.559  0.297  1.0
  Nb  Nb3  1  0.780  0.441  0.703  1.0
  Nb  Nb4  1  0.894  0.212  0.290  1.0
  N  N5  1  0.623  0.754  0.778  1.0
  N  N6  1  0.267  0.466  0.645  1.0
  N  N7  1  0.733  0.534  0.355  1.0
  N  N8  1  0.377  0.246  0.222  1.0
  O  O9  1  0.063  0.873  0.390  1.0
  O  O10  1  0.110  0.781  0.031  1.0
  O  O11  1  0.890  0.219  0.969  1.0
  O  O12  1  0.937  0.127  0.610  1.0
[/CIF]
.