The material described by La3NbO7 crystallizes in the orthorhombic Pnma space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent La(1)O7 pentagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent La(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 31-42°. In the second La site, La(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent La(1)O7 pentagonal bipyramids, and edges with four equivalent La(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 32°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form OLa4 tetrahedra that share corners with four equivalent O(2)La3Nb tetrahedra, corners with six equivalent O(1)La4 tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(2)La3Nb tetrahedra. In the second O site, O(2) is bonded to one La(2), two equivalent La(1), and one Nb(1) atom to form distorted OLa3Nb tetrahedra that share corners with four equivalent O(1)La4 tetrahedra, edges with two equivalent O(2)La3Nb tetrahedra, and edges with two equivalent O(1)La4 tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Nb(1) atoms. is represented by the CIF file [CIF]
data_La3NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.697
_cell_length_b   7.782
_cell_length_c   11.166
_cell_angle_alpha   90.000
_cell_angle_beta   90.001
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   668.856
_cell_formula_units_Z   4
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
  La  La0  1  0.047  0.751  0.477  1.0
  La  La1  1  0.280  0.492  0.750  1.0
  La  La2  1  0.720  0.508  0.250  1.0
  La  La3  1  0.453  0.251  0.024  1.0
  La  La4  1  0.780  0.008  0.250  1.0
  La  La5  1  0.547  0.749  0.523  1.0
  La  La6  1  0.547  0.749  0.977  1.0
  La  La7  1  0.047  0.751  0.023  1.0
  La  La8  1  0.953  0.249  0.977  1.0
  La  La9  1  0.953  0.249  0.523  1.0
  La  La10  1  0.453  0.251  0.477  1.0
  La  La11  1  0.220  0.992  0.750  1.0
  Nb  Nb12  1  0.749  0.994  0.750  1.0
  Nb  Nb13  1  0.251  0.006  0.250  1.0
  Nb  Nb14  1  0.751  0.494  0.750  1.0
  Nb  Nb15  1  0.249  0.506  0.250  1.0
  O  O16  1  0.227  0.246  0.619  1.0
  O  O17  1  0.550  0.466  0.628  1.0
  O  O18  1  0.590  0.040  0.617  1.0
  O  O19  1  0.410  0.960  0.383  1.0
  O  O20  1  0.050  0.034  0.372  1.0
  O  O21  1  0.910  0.540  0.883  1.0
  O  O22  1  0.323  0.247  0.250  1.0
  O  O23  1  0.773  0.754  0.381  1.0
  O  O24  1  0.950  0.966  0.628  1.0
  O  O25  1  0.273  0.746  0.881  1.0
  O  O26  1  0.727  0.254  0.119  1.0
  O  O27  1  0.227  0.245  0.881  1.0
  O  O28  1  0.823  0.253  0.750  1.0
  O  O29  1  0.090  0.460  0.117  1.0
  O  O30  1  0.727  0.254  0.381  1.0
  O  O31  1  0.050  0.034  0.128  1.0
  O  O32  1  0.950  0.966  0.872  1.0
  O  O33  1  0.677  0.753  0.750  1.0
  O  O34  1  0.273  0.746  0.619  1.0
  O  O35  1  0.177  0.747  0.250  1.0
  O  O36  1  0.450  0.534  0.372  1.0
  O  O37  1  0.910  0.540  0.617  1.0
  O  O38  1  0.090  0.460  0.383  1.0
  O  O39  1  0.590  0.040  0.883  1.0
  O  O40  1  0.450  0.534  0.128  1.0
  O  O41  1  0.410  0.960  0.117  1.0
  O  O42  1  0.550  0.466  0.872  1.0
  O  O43  1  0.773  0.754  0.119  1.0
[/CIF]
.
The material described by La3NbO7 crystallizes in the orthorhombic Pnma space group. There are two inequivalent La sites. In the first La site, La(1) is bonded to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent La(1)O7 pentagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with two equivalent La(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 31-42°. In the second La site, La(2) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent La(1)O7 pentagonal bipyramids, and edges with four equivalent La(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 32°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form OLa4 tetrahedra that share corners with four equivalent O(2)La3Nb tetrahedra, corners with six equivalent O(1)La4 tetrahedra,  an edgeedge with one O(1)La4 tetrahedra, and edges with two equivalent O(2)La3Nb tetrahedra. In the second O site, O(2) is bonded to one La(2), two equivalent La(1), and one Nb(1) atom to form distorted OLa3Nb tetrahedra that share corners with four equivalent O(1)La4 tetrahedra, edges with two equivalent O(2)La3Nb tetrahedra, and edges with two equivalent O(1)La4 tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent La(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent La(1) and two equivalent Nb(1) atoms. is represented by the CIF file [CIF]
data_La3NbO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.697
_cell_length_b   7.782
_cell_length_c   11.166
_cell_angle_alpha   90.000
_cell_angle_beta   90.001
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   668.856
_cell_formula_units_Z   4
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
  La  La0  1  0.047  0.751  0.477  1.0
  La  La1  1  0.280  0.492  0.750  1.0
  La  La2  1  0.720  0.508  0.250  1.0
  La  La3  1  0.453  0.251  0.024  1.0
  La  La4  1  0.780  0.008  0.250  1.0
  La  La5  1  0.547  0.749  0.523  1.0
  La  La6  1  0.547  0.749  0.977  1.0
  La  La7  1  0.047  0.751  0.023  1.0
  La  La8  1  0.953  0.249  0.977  1.0
  La  La9  1  0.953  0.249  0.523  1.0
  La  La10  1  0.453  0.251  0.477  1.0
  La  La11  1  0.220  0.992  0.750  1.0
  Nb  Nb12  1  0.749  0.994  0.750  1.0
  Nb  Nb13  1  0.251  0.006  0.250  1.0
  Nb  Nb14  1  0.751  0.494  0.750  1.0
  Nb  Nb15  1  0.249  0.506  0.250  1.0
  O  O16  1  0.227  0.246  0.619  1.0
  O  O17  1  0.550  0.466  0.628  1.0
  O  O18  1  0.590  0.040  0.617  1.0
  O  O19  1  0.410  0.960  0.383  1.0
  O  O20  1  0.050  0.034  0.372  1.0
  O  O21  1  0.910  0.540  0.883  1.0
  O  O22  1  0.323  0.247  0.250  1.0
  O  O23  1  0.773  0.754  0.381  1.0
  O  O24  1  0.950  0.966  0.628  1.0
  O  O25  1  0.273  0.746  0.881  1.0
  O  O26  1  0.727  0.254  0.119  1.0
  O  O27  1  0.227  0.245  0.881  1.0
  O  O28  1  0.823  0.253  0.750  1.0
  O  O29  1  0.090  0.460  0.117  1.0
  O  O30  1  0.727  0.254  0.381  1.0
  O  O31  1  0.050  0.034  0.128  1.0
  O  O32  1  0.950  0.966  0.872  1.0
  O  O33  1  0.677  0.753  0.750  1.0
  O  O34  1  0.273  0.746  0.619  1.0
  O  O35  1  0.177  0.747  0.250  1.0
  O  O36  1  0.450  0.534  0.372  1.0
  O  O37  1  0.910  0.540  0.617  1.0
  O  O38  1  0.090  0.460  0.383  1.0
  O  O39  1  0.590  0.040  0.883  1.0
  O  O40  1  0.450  0.534  0.128  1.0
  O  O41  1  0.410  0.960  0.117  1.0
  O  O42  1  0.550  0.466  0.872  1.0
  O  O43  1  0.773  0.754  0.119  1.0
[/CIF]
.