The structure described by Ba2MgEuNbO6 is Krennerite-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form distorted MgO5 trigonal bipyramids that share corners with three equivalent Nb(1)O6 octahedra,  a cornercorner with one Eu(1)O6 pentagonal pyramid,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Eu(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 4-10°. Eu(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted EuO6 pentagonal pyramids that share corners with three equivalent Nb(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-18°. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with three equivalent Eu(1)O6 pentagonal pyramids, corners with three equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  a faceface with one Eu(1)O6 pentagonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom. In the second O site, O(2) is bonded to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom to form distorted corner-sharing OBa3EuMgNb octahedra. The corner-sharing octahedral tilt angles are 15°. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(1), two equivalent Ba(2), one Mg(1), one Eu(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(1), two equivalent Ba(2), one Mg(1), one Eu(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ba(2), one Eu(1), and one Nb(1) atom. is represented by the CIF file [CIF]
data_Ba2EuMgNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.002
_cell_length_b   6.763
_cell_length_c   8.920
_cell_angle_alpha   137.507
_cell_angle_beta   132.614
_cell_angle_gamma   63.565
_symmetry_Int_Tables_number   1
_cell_volume   178.915
_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
  Ba  Ba0  1  0.722  0.292  0.642  1.0
  Ba  Ba1  1  0.252  0.765  0.408  1.0
  Eu  Eu2  1  0.134  0.876  0.846  1.0
  Mg  Mg3  1  0.847  0.115  0.184  1.0
  Nb  Nb4  1  0.495  0.518  0.028  1.0
  O  O5  1  0.663  0.788  0.070  1.0
  O  O6  1  0.178  0.828  0.112  1.0
  O  O7  1  0.775  0.204  0.936  1.0
  O  O8  1  0.373  0.257  0.010  1.0
  O  O9  1  0.141  0.329  0.607  1.0
  O  O10  1  0.815  0.736  0.421  1.0
[/CIF]
.
The structure described by Ba2MgEuNbO6 is Krennerite-derived structured and crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form distorted MgO5 trigonal bipyramids that share corners with three equivalent Nb(1)O6 octahedra,  a cornercorner with one Eu(1)O6 pentagonal pyramid,  an edgeedge with one Nb(1)O6 octahedra, and edges with two equivalent Eu(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 4-10°. Eu(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted EuO6 pentagonal pyramids that share corners with three equivalent Nb(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-18°. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with three equivalent Eu(1)O6 pentagonal pyramids, corners with three equivalent Mg(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  a faceface with one Eu(1)O6 pentagonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom. In the second O site, O(2) is bonded to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom to form distorted corner-sharing OBa3EuMgNb octahedra. The corner-sharing octahedral tilt angles are 15°. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(1), two equivalent Ba(2), one Mg(1), one Eu(1), and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Ba(1), two equivalent Ba(2), one Mg(1), one Eu(1), and one Nb(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Ba(2), two equivalent Ba(1), one Mg(1), one Eu(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Ba(2), one Eu(1), and one Nb(1) atom. is represented by the CIF file [CIF]
data_Ba2EuMgNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.002
_cell_length_b   6.763
_cell_length_c   8.920
_cell_angle_alpha   137.507
_cell_angle_beta   132.614
_cell_angle_gamma   63.565
_symmetry_Int_Tables_number   1
_cell_volume   178.915
_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
  Ba  Ba0  1  0.722  0.292  0.642  1.0
  Ba  Ba1  1  0.252  0.765  0.408  1.0
  Eu  Eu2  1  0.134  0.876  0.846  1.0
  Mg  Mg3  1  0.847  0.115  0.184  1.0
  Nb  Nb4  1  0.495  0.518  0.028  1.0
  O  O5  1  0.663  0.788  0.070  1.0
  O  O6  1  0.178  0.828  0.112  1.0
  O  O7  1  0.775  0.204  0.936  1.0
  O  O8  1  0.373  0.257  0.010  1.0
  O  O9  1  0.141  0.329  0.607  1.0
  O  O10  1  0.815  0.736  0.421  1.0
[/CIF]
.