The material described by Mg2NbN3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(3)N6 octahedra, corners with four equivalent Nb(1)N6 octahedra, edges with two equivalent Mg(3)N6 octahedra, edges with three equivalent Mg(1)N6 octahedra, edges with three equivalent Mg(2)N6 octahedra, and edges with four equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the second Mg site, Mg(2) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(3)N6 octahedra, corners with four equivalent Nb(1)N6 octahedra, edges with two equivalent Mg(3)N6 octahedra, edges with four equivalent Nb(1)N6 octahedra, and edges with six equivalent Mg(1)N6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the third Mg site, Mg(3) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(2)N6 octahedra, corners with four equivalent Mg(1)N6 octahedra, edges with two equivalent Mg(2)N6 octahedra, edges with four equivalent Mg(1)N6 octahedra, and edges with six equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. Nb(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form NbN6 octahedra that share corners with two equivalent Mg(2)N6 octahedra, corners with four equivalent Mg(1)N6 octahedra, edges with two equivalent Mg(2)N6 octahedra, edges with three equivalent Mg(3)N6 octahedra, edges with three equivalent Nb(1)N6 octahedra, and edges with four equivalent Mg(1)N6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Mg(2), one Mg(3), two equivalent Mg(1), and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing NMg4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the second N site, N(2) is bonded to one Mg(2), one Mg(3), two equivalent Mg(1), and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing NMg4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2NbN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.398
_cell_length_b   5.398
_cell_length_c   5.397
_cell_angle_alpha   99.691
_cell_angle_beta   99.691
_cell_angle_gamma   119.925
_symmetry_Int_Tables_number   1
_cell_volume   128.354
_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
  Mg  Mg0  1  0.837  0.163  0.500  1.0
  Mg  Mg1  1  0.163  0.837  0.500  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
  Nb  Nb4  1  0.332  0.668  0.000  1.0
  Nb  Nb5  1  0.668  0.332  0.000  1.0
  N  N6  1  0.425  0.078  0.235  1.0
  N  N7  1  0.922  0.575  0.765  1.0
  N  N8  1  0.575  0.922  0.765  1.0
  N  N9  1  0.078  0.425  0.235  1.0
  N  N10  1  0.734  0.734  0.240  1.0
  N  N11  1  0.266  0.266  0.760  1.0
[/CIF]
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The material described by Mg2NbN3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(3)N6 octahedra, corners with four equivalent Nb(1)N6 octahedra, edges with two equivalent Mg(3)N6 octahedra, edges with three equivalent Mg(1)N6 octahedra, edges with three equivalent Mg(2)N6 octahedra, and edges with four equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the second Mg site, Mg(2) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(3)N6 octahedra, corners with four equivalent Nb(1)N6 octahedra, edges with two equivalent Mg(3)N6 octahedra, edges with four equivalent Nb(1)N6 octahedra, and edges with six equivalent Mg(1)N6 octahedra. The corner-sharing octahedral tilt angles are 4°. In the third Mg site, Mg(3) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form MgN6 octahedra that share corners with two equivalent Mg(2)N6 octahedra, corners with four equivalent Mg(1)N6 octahedra, edges with two equivalent Mg(2)N6 octahedra, edges with four equivalent Mg(1)N6 octahedra, and edges with six equivalent Nb(1)N6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. Nb(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form NbN6 octahedra that share corners with two equivalent Mg(2)N6 octahedra, corners with four equivalent Mg(1)N6 octahedra, edges with two equivalent Mg(2)N6 octahedra, edges with three equivalent Mg(3)N6 octahedra, edges with three equivalent Nb(1)N6 octahedra, and edges with four equivalent Mg(1)N6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are two inequivalent N sites. In the first N site, N(1) is bonded to one Mg(2), one Mg(3), two equivalent Mg(1), and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing NMg4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the second N site, N(2) is bonded to one Mg(2), one Mg(3), two equivalent Mg(1), and two equivalent Nb(1) atoms to form a mixture of corner and edge-sharing NMg4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2NbN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.398
_cell_length_b   5.398
_cell_length_c   5.397
_cell_angle_alpha   99.691
_cell_angle_beta   99.691
_cell_angle_gamma   119.925
_symmetry_Int_Tables_number   1
_cell_volume   128.354
_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
  Mg  Mg0  1  0.837  0.163  0.500  1.0
  Mg  Mg1  1  0.163  0.837  0.500  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
  Nb  Nb4  1  0.332  0.668  0.000  1.0
  Nb  Nb5  1  0.668  0.332  0.000  1.0
  N  N6  1  0.425  0.078  0.235  1.0
  N  N7  1  0.922  0.575  0.765  1.0
  N  N8  1  0.575  0.922  0.765  1.0
  N  N9  1  0.078  0.425  0.235  1.0
  N  N10  1  0.734  0.734  0.240  1.0
  N  N11  1  0.266  0.266  0.760  1.0
[/CIF]
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