The structure described by Eu2Nb4O13 crystallizes in the triclinic P1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 6-coordinate geometry to one O(10), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to one O(12), one O(13), one O(2), one O(3), one O(5), and one O(7) atom. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted octahedral geometry to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom. In the second Nb site, Nb(2) is bonded to one O(12), one O(13), one O(2), one O(3), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 21°. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(13), one O(2), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 21°. In the fourth Nb site, Nb(4) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(4), one O(5), and one O(9) atom. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(4) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Eu(2), one Nb(2), and one Nb(3) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Eu(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Nb(1), and one Nb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Nb(1), and one Nb(4) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Eu(1), one Eu(2), one Nb(2), and one Nb(3) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Eu(1) and one Nb(1) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Nb(1) and one Nb(4) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Nb(1), and one Nb(4) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(3) and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Eu(2), one Nb(2), and one Nb(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Eu(2), one Nb(2), and one Nb(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2Nb4O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.395
_cell_length_b   5.768
_cell_length_c   10.075
_cell_angle_alpha   90.034
_cell_angle_beta   94.954
_cell_angle_gamma   113.437
_symmetry_Int_Tables_number   1
_cell_volume   286.358
_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
  Eu  Eu0  1  0.550  0.002  0.349  1.0
  Eu  Eu1  1  0.010  0.393  0.144  1.0
  Nb  Nb2  1  0.906  0.697  0.475  1.0
  Nb  Nb3  1  0.602  0.775  0.024  1.0
  Nb  Nb4  1  0.370  0.190  0.939  1.0
  Nb  Nb5  1  0.176  0.302  0.576  1.0
  O  O6  1  0.511  0.524  0.489  1.0
  O  O7  1  0.258  0.491  0.960  1.0
  O  O8  1  0.456  0.648  0.195  1.0
  O  O9  1  0.830  0.014  0.547  1.0
  O  O10  1  0.945  0.411  0.376  1.0
  O  O11  1  0.494  0.938  0.874  1.0
  O  O12  1  0.560  0.094  0.115  1.0
  O  O13  1  0.928  0.867  0.301  1.0
  O  O14  1  0.054  0.559  0.627  1.0
  O  O15  1  0.268  1.000  0.500  1.0
  O  O16  1  0.297  0.241  0.748  1.0
  O  O17  1  0.020  0.012  0.016  1.0
  O  O18  1  0.723  0.497  0.981  1.0
[/CIF]
.
The structure described by Eu2Nb4O13 crystallizes in the triclinic P1 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 6-coordinate geometry to one O(10), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the second Eu site, Eu(2) is bonded in a 6-coordinate geometry to one O(12), one O(13), one O(2), one O(3), one O(5), and one O(7) atom. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted octahedral geometry to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom. In the second Nb site, Nb(2) is bonded to one O(12), one O(13), one O(2), one O(3), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 21°. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(13), one O(2), one O(6), and one O(7) atom to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 21°. In the fourth Nb site, Nb(4) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(4), one O(5), and one O(9) atom. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one Nb(4) atom. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Eu(2), one Nb(2), and one Nb(3) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Eu(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Nb(1), and one Nb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Eu(1), one Eu(2), one Nb(1), and one Nb(4) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one Nb(2) and one Nb(3) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Eu(1), one Eu(2), one Nb(2), and one Nb(3) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Eu(1) and one Nb(1) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Nb(1) and one Nb(4) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one Eu(1), one Nb(1), and one Nb(4) atom. In the eleventh O site, O(11) is bonded in a linear geometry to one Nb(3) and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Eu(2), one Nb(2), and one Nb(3) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Eu(2), one Nb(2), and one Nb(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Eu2Nb4O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.395
_cell_length_b   5.768
_cell_length_c   10.075
_cell_angle_alpha   90.034
_cell_angle_beta   94.954
_cell_angle_gamma   113.437
_symmetry_Int_Tables_number   1
_cell_volume   286.358
_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
  Eu  Eu0  1  0.550  0.002  0.349  1.0
  Eu  Eu1  1  0.010  0.393  0.144  1.0
  Nb  Nb2  1  0.906  0.697  0.475  1.0
  Nb  Nb3  1  0.602  0.775  0.024  1.0
  Nb  Nb4  1  0.370  0.190  0.939  1.0
  Nb  Nb5  1  0.176  0.302  0.576  1.0
  O  O6  1  0.511  0.524  0.489  1.0
  O  O7  1  0.258  0.491  0.960  1.0
  O  O8  1  0.456  0.648  0.195  1.0
  O  O9  1  0.830  0.014  0.547  1.0
  O  O10  1  0.945  0.411  0.376  1.0
  O  O11  1  0.494  0.938  0.874  1.0
  O  O12  1  0.560  0.094  0.115  1.0
  O  O13  1  0.928  0.867  0.301  1.0
  O  O14  1  0.054  0.559  0.627  1.0
  O  O15  1  0.268  1.000  0.500  1.0
  O  O16  1  0.297  0.241  0.748  1.0
  O  O17  1  0.020  0.012  0.016  1.0
  O  O18  1  0.723  0.497  0.981  1.0
[/CIF]
.