The compound described by Eu2NbGaO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted EuO8 hexagonal bipyramids that share edges with two equivalent Eu(1)O8 hexagonal bipyramids, edges with four equivalent Eu(2)O8 hexagonal bipyramids, edges with two equivalent Ga(1)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. In the second Eu site, Eu(2) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms to form distorted EuO8 hexagonal bipyramids that share edges with two equivalent Eu(2)O8 hexagonal bipyramids, edges with four equivalent Eu(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with four equivalent Ga(1)O6 octahedra. Nb(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Ga(1)O6 octahedra, edges with two equivalent Eu(2)O8 hexagonal bipyramids, and edges with four equivalent Eu(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-47°. Ga(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form GaO6 octahedra that share corners with two equivalent Ga(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, edges with two equivalent Eu(1)O8 hexagonal bipyramids, and edges with four equivalent Eu(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1) and two equivalent Eu(2) atoms to form OEu4 tetrahedra that share corners with two equivalent O(3)Eu2Ga2 tetrahedra, corners with two equivalent O(2)Eu2Nb2 tetrahedra, corners with four equivalent O(1)Eu4 tetrahedra,  an edgeedge with one O(3)Eu2Ga2 tetrahedra, and  an edgeedge with one O(2)Eu2Nb2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Eu(1) and two equivalent Nb(1) atoms to form distorted OEu2Nb2 tetrahedra that share corners with two equivalent O(1)Eu4 tetrahedra, corners with four equivalent O(2)Eu2Nb2 tetrahedra, and  an edgeedge with one O(1)Eu4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Eu(2) and two equivalent Ga(1) atoms to form distorted OEu2Ga2 tetrahedra that share corners with two equivalent O(1)Eu4 tetrahedra, corners with four equivalent O(3)Eu2Ga2 tetrahedra, and  an edgeedge with one O(1)Eu4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Nb(1), and one Ga(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2NbGaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.302
_cell_length_c   7.484
_cell_angle_alpha   90.000
_cell_angle_beta   59.614
_cell_angle_gamma   119.576
_symmetry_Int_Tables_number   1
_cell_volume   285.993
_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
  Eu  Eu0  1  0.500  0.000  0.500  1.0
  Eu  Eu1  1  0.500  0.500  0.500  1.0
  Eu  Eu2  1  0.000  0.500  0.000  1.0
  Eu  Eu3  1  0.000  0.500  0.500  1.0
  Nb  Nb4  1  0.000  0.000  0.500  1.0
  Nb  Nb5  1  0.000  0.000  0.000  1.0
  Ga  Ga6  1  0.500  0.500  0.000  1.0
  Ga  Ga7  1  0.500  0.000  0.000  1.0
  O  O8  1  0.750  0.375  0.375  1.0
  O  O9  1  0.250  0.625  0.625  1.0
  O  O10  1  0.847  0.924  0.326  1.0
  O  O11  1  0.662  0.331  0.919  1.0
  O  O12  1  0.250  0.923  0.923  1.0
  O  O13  1  0.250  0.326  0.327  1.0
  O  O14  1  0.250  0.326  0.923  1.0
  O  O15  1  0.250  0.923  0.327  1.0
  O  O16  1  0.153  0.076  0.674  1.0
  O  O17  1  0.338  0.669  0.081  1.0
  O  O18  1  0.750  0.077  0.077  1.0
  O  O19  1  0.750  0.674  0.673  1.0
  O  O20  1  0.750  0.674  0.077  1.0
  O  O21  1  0.750  0.077  0.673  1.0
[/CIF]
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The compound described by Eu2NbGaO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted EuO8 hexagonal bipyramids that share edges with two equivalent Eu(1)O8 hexagonal bipyramids, edges with four equivalent Eu(2)O8 hexagonal bipyramids, edges with two equivalent Ga(1)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. In the second Eu site, Eu(2) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms to form distorted EuO8 hexagonal bipyramids that share edges with two equivalent Eu(2)O8 hexagonal bipyramids, edges with four equivalent Eu(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with four equivalent Ga(1)O6 octahedra. Nb(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Ga(1)O6 octahedra, edges with two equivalent Eu(2)O8 hexagonal bipyramids, and edges with four equivalent Eu(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-47°. Ga(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form GaO6 octahedra that share corners with two equivalent Ga(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, edges with two equivalent Eu(1)O8 hexagonal bipyramids, and edges with four equivalent Eu(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 47-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Eu(1) and two equivalent Eu(2) atoms to form OEu4 tetrahedra that share corners with two equivalent O(3)Eu2Ga2 tetrahedra, corners with two equivalent O(2)Eu2Nb2 tetrahedra, corners with four equivalent O(1)Eu4 tetrahedra,  an edgeedge with one O(3)Eu2Ga2 tetrahedra, and  an edgeedge with one O(2)Eu2Nb2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Eu(1) and two equivalent Nb(1) atoms to form distorted OEu2Nb2 tetrahedra that share corners with two equivalent O(1)Eu4 tetrahedra, corners with four equivalent O(2)Eu2Nb2 tetrahedra, and  an edgeedge with one O(1)Eu4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Eu(2) and two equivalent Ga(1) atoms to form distorted OEu2Ga2 tetrahedra that share corners with two equivalent O(1)Eu4 tetrahedra, corners with four equivalent O(3)Eu2Ga2 tetrahedra, and  an edgeedge with one O(1)Eu4 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Nb(1), and one Ga(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2NbGaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.302
_cell_length_c   7.484
_cell_angle_alpha   90.000
_cell_angle_beta   59.614
_cell_angle_gamma   119.576
_symmetry_Int_Tables_number   1
_cell_volume   285.993
_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
  Eu  Eu0  1  0.500  0.000  0.500  1.0
  Eu  Eu1  1  0.500  0.500  0.500  1.0
  Eu  Eu2  1  0.000  0.500  0.000  1.0
  Eu  Eu3  1  0.000  0.500  0.500  1.0
  Nb  Nb4  1  0.000  0.000  0.500  1.0
  Nb  Nb5  1  0.000  0.000  0.000  1.0
  Ga  Ga6  1  0.500  0.500  0.000  1.0
  Ga  Ga7  1  0.500  0.000  0.000  1.0
  O  O8  1  0.750  0.375  0.375  1.0
  O  O9  1  0.250  0.625  0.625  1.0
  O  O10  1  0.847  0.924  0.326  1.0
  O  O11  1  0.662  0.331  0.919  1.0
  O  O12  1  0.250  0.923  0.923  1.0
  O  O13  1  0.250  0.326  0.327  1.0
  O  O14  1  0.250  0.326  0.923  1.0
  O  O15  1  0.250  0.923  0.327  1.0
  O  O16  1  0.153  0.076  0.674  1.0
  O  O17  1  0.338  0.669  0.081  1.0
  O  O18  1  0.750  0.077  0.077  1.0
  O  O19  1  0.750  0.674  0.673  1.0
  O  O20  1  0.750  0.674  0.077  1.0
  O  O21  1  0.750  0.077  0.673  1.0
[/CIF]
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