The material structure described by MgNb2(GaO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(2), one O(5), one O(7), and two equivalent O(1) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Ga(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Nb(2)O6 octahedra, and edges with two equivalent Ga(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ga(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-26°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(7) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ga(2)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(1)O6 octahedra,  an edgeedge with one Ga(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-28°. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), and two equivalent O(6) atoms to form distorted GaO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ga(2)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 17-74°. In the second Ga site, Ga(2) is bonded to one O(1), one O(3), one O(6), one O(8), and two equivalent O(5) atoms to form distorted GaO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Ga(2)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-32°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Nb(2), and one Ga(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Nb(1), and one Ga(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Ga(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Ga(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Nb(1), and two equivalent Ga(2) atoms. In the sixth O site, O(6) is bonded to one Nb(2), one Ga(2), and two equivalent Ga(1) atoms to form distorted corner-sharing ONbGa3 tetrahedra. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Nb(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Ga(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb2(GaO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.824
_cell_length_b   7.096
_cell_length_c   6.895
_cell_angle_alpha   109.986
_cell_angle_beta   90.004
_cell_angle_gamma   105.625
_symmetry_Int_Tables_number   1
_cell_volume   168.451
_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  0.304  0.613  0.489  1.0
  Nb  Nb1  1  0.090  0.183  0.176  1.0
  Nb  Nb2  1  0.910  0.824  0.843  1.0
  Ga  Ga3  1  0.178  0.361  0.775  1.0
  Ga  Ga4  1  0.799  0.603  0.180  1.0
  O  O5  1  0.849  0.702  0.491  1.0
  O  O6  1  0.159  0.323  0.498  1.0
  O  O7  1  0.935  0.874  0.152  1.0
  O  O8  1  0.060  0.124  0.853  1.0
  O  O9  1  0.258  0.520  0.175  1.0
  O  O10  1  0.741  0.486  0.865  1.0
  O  O11  1  0.374  0.752  0.803  1.0
  O  O12  1  0.621  0.245  0.170  1.0
[/CIF]
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The material structure described by MgNb2(GaO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(2), one O(5), one O(7), and two equivalent O(1) atoms to form MgO5 trigonal bipyramids that share  a cornercorner with one Ga(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Nb(1)O6 octahedra, edges with two equivalent Nb(2)O6 octahedra, and edges with two equivalent Ga(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(8) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ga(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Ga(2)O6 octahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-26°. In the second Nb site, Nb(2) is bonded to one O(1), one O(3), one O(4), one O(6), and two equivalent O(7) atoms to form distorted NbO6 octahedra that share  a cornercorner with one Ga(2)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(1)O6 octahedra,  an edgeedge with one Ga(2)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-28°. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), and two equivalent O(6) atoms to form distorted GaO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ga(2)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 17-74°. In the second Ga site, Ga(2) is bonded to one O(1), one O(3), one O(6), one O(8), and two equivalent O(5) atoms to form distorted GaO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Nb(2)O6 octahedra, corners with two equivalent Ga(2)O6 octahedra, corners with two equivalent Ga(1)O4 tetrahedra,  an edgeedge with one Nb(2)O6 octahedra, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 2-32°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1), one Nb(2), and one Ga(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Nb(1), and one Ga(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Ga(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Ga(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Nb(1), and two equivalent Ga(2) atoms. In the sixth O site, O(6) is bonded to one Nb(2), one Ga(2), and two equivalent Ga(1) atoms to form distorted corner-sharing ONbGa3 tetrahedra. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Nb(2) atoms. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Ga(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb2(GaO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.824
_cell_length_b   7.096
_cell_length_c   6.895
_cell_angle_alpha   109.986
_cell_angle_beta   90.004
_cell_angle_gamma   105.625
_symmetry_Int_Tables_number   1
_cell_volume   168.451
_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  0.304  0.613  0.489  1.0
  Nb  Nb1  1  0.090  0.183  0.176  1.0
  Nb  Nb2  1  0.910  0.824  0.843  1.0
  Ga  Ga3  1  0.178  0.361  0.775  1.0
  Ga  Ga4  1  0.799  0.603  0.180  1.0
  O  O5  1  0.849  0.702  0.491  1.0
  O  O6  1  0.159  0.323  0.498  1.0
  O  O7  1  0.935  0.874  0.152  1.0
  O  O8  1  0.060  0.124  0.853  1.0
  O  O9  1  0.258  0.520  0.175  1.0
  O  O10  1  0.741  0.486  0.865  1.0
  O  O11  1  0.374  0.752  0.803  1.0
  O  O12  1  0.621  0.245  0.170  1.0
[/CIF]
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