The structure described by Ba6Mg7H26 crystallizes in the orthorhombic Immm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to one H(5), one H(7), two equivalent H(2), two equivalent H(3), two equivalent H(4), and four equivalent H(1) atoms. In the second Ba site, Ba(2) is bonded to two equivalent H(4), two equivalent H(7), four equivalent H(1), and four equivalent H(2) atoms to form distorted BaH12 cuboctahedra that share corners with two equivalent Ba(2)H12 cuboctahedra,  a faceface with one Ba(2)H12 cuboctahedra, faces with two equivalent Mg(2)H6 octahedra, and faces with two equivalent Mg(4)H6 octahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one H(6), one H(7), and four equivalent H(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms to form MgH6 octahedra that share corners with two equivalent Mg(3)H6 octahedra, corners with two equivalent Mg(4)H6 octahedra, and faces with two equivalent Ba(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 3-55°. In the third Mg site, Mg(3) is bonded to two equivalent H(3), two equivalent H(5), and two equivalent H(6) atoms to form a mixture of edge and corner-sharing MgH6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the fourth Mg site, Mg(4) is bonded to two equivalent H(7) and four equivalent H(2) atoms to form MgH6 octahedra that share corners with four equivalent Mg(2)H6 octahedra and faces with four equivalent Ba(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are seven inequivalent H sites. In the first H site, H(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(2), and one Mg(4) atom. In the second H site, H(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Mg(2), and one Mg(3) atom. In the third H site, H(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Mg(2) atom. In the fourth H site, H(5) is bonded in an L-shaped geometry to two equivalent Ba(1) and two equivalent Mg(3) atoms. In the fifth H site, H(6) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mg(3) atoms. In the sixth H site, H(7) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(1), and one Mg(4) atom. In the seventh H site, H(1) is bonded to one Ba(2), two equivalent Ba(1), and one Mg(1) atom to form a mixture of distorted edge and corner-sharing HBa3Mg tetrahedra. is represented by the CIF file [CIF]
data_Ba6Mg7H26
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.994
_cell_length_b   9.994
_cell_length_c   9.994
_cell_angle_alpha   146.274
_cell_angle_beta   106.637
_cell_angle_gamma   83.223
_symmetry_Int_Tables_number   1
_cell_volume   517.262
_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  0.907  0.648  0.259  1.0
  Ba  Ba1  1  0.093  0.352  0.741  1.0
  Ba  Ba2  1  0.612  0.352  0.259  1.0
  Ba  Ba3  1  0.388  0.648  0.741  1.0
  Ba  Ba4  1  0.644  0.144  0.500  1.0
  Ba  Ba5  1  0.356  0.856  0.500  1.0
  Mg  Mg6  1  0.782  0.782  1.000  1.0
  Mg  Mg7  1  0.218  0.218  0.000  1.0
  Mg  Mg8  1  0.258  0.000  0.258  1.0
  Mg  Mg9  1  0.742  1.000  0.742  1.0
  Mg  Mg10  1  1.000  0.254  0.254  1.0
  Mg  Mg11  1  0.000  0.746  0.746  1.0
  Mg  Mg12  1  0.500  0.500  1.000  1.0
  H  H13  1  0.867  0.985  0.342  1.0
  H  H14  1  0.133  0.476  0.119  1.0
  H  H15  1  0.357  0.015  0.881  1.0
  H  H16  1  0.643  0.524  0.658  1.0
  H  H17  1  0.133  0.015  0.658  1.0
  H  H18  1  0.867  0.524  0.881  1.0
  H  H19  1  0.643  0.985  0.119  1.0
  H  H20  1  0.357  0.476  0.342  1.0
  H  H21  1  0.385  0.250  0.635  1.0
  H  H22  1  0.615  0.250  0.864  1.0
  H  H23  1  0.385  0.750  0.136  1.0
  H  H24  1  0.615  0.750  0.365  1.0
  H  H25  1  0.162  0.264  0.426  1.0
  H  H26  1  0.838  0.264  0.102  1.0
  H  H27  1  0.162  0.736  0.898  1.0
  H  H28  1  0.838  0.736  0.574  1.0
  H  H29  1  0.148  0.873  0.275  1.0
  H  H30  1  0.852  0.127  0.725  1.0
  H  H31  1  0.402  0.127  0.275  1.0
  H  H32  1  0.598  0.873  0.725  1.0
  H  H33  1  0.911  0.411  0.500  1.0
  H  H34  1  0.089  0.589  0.500  1.0
  H  H35  1  0.913  0.913  0.000  1.0
  H  H36  1  0.087  0.087  1.000  1.0
  H  H37  1  0.629  0.629  0.000  1.0
  H  H38  1  0.371  0.371  1.000  1.0
[/CIF]
.
The structure described by Ba6Mg7H26 crystallizes in the orthorhombic Immm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 12-coordinate geometry to one H(5), one H(7), two equivalent H(2), two equivalent H(3), two equivalent H(4), and four equivalent H(1) atoms. In the second Ba site, Ba(2) is bonded to two equivalent H(4), two equivalent H(7), four equivalent H(1), and four equivalent H(2) atoms to form distorted BaH12 cuboctahedra that share corners with two equivalent Ba(2)H12 cuboctahedra,  a faceface with one Ba(2)H12 cuboctahedra, faces with two equivalent Mg(2)H6 octahedra, and faces with two equivalent Mg(4)H6 octahedra. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one H(6), one H(7), and four equivalent H(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent H(2), two equivalent H(3), and two equivalent H(4) atoms to form MgH6 octahedra that share corners with two equivalent Mg(3)H6 octahedra, corners with two equivalent Mg(4)H6 octahedra, and faces with two equivalent Ba(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles range from 3-55°. In the third Mg site, Mg(3) is bonded to two equivalent H(3), two equivalent H(5), and two equivalent H(6) atoms to form a mixture of edge and corner-sharing MgH6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the fourth Mg site, Mg(4) is bonded to two equivalent H(7) and four equivalent H(2) atoms to form MgH6 octahedra that share corners with four equivalent Mg(2)H6 octahedra and faces with four equivalent Ba(2)H12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are seven inequivalent H sites. In the first H site, H(2) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(2), and one Mg(4) atom. In the second H site, H(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Mg(2), and one Mg(3) atom. In the third H site, H(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one Mg(2) atom. In the fourth H site, H(5) is bonded in an L-shaped geometry to two equivalent Ba(1) and two equivalent Mg(3) atoms. In the fifth H site, H(6) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mg(3) atoms. In the sixth H site, H(7) is bonded in a 1-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), one Mg(1), and one Mg(4) atom. In the seventh H site, H(1) is bonded to one Ba(2), two equivalent Ba(1), and one Mg(1) atom to form a mixture of distorted edge and corner-sharing HBa3Mg tetrahedra. is represented by the CIF file [CIF]
data_Ba6Mg7H26
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.994
_cell_length_b   9.994
_cell_length_c   9.994
_cell_angle_alpha   146.274
_cell_angle_beta   106.637
_cell_angle_gamma   83.223
_symmetry_Int_Tables_number   1
_cell_volume   517.262
_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  0.907  0.648  0.259  1.0
  Ba  Ba1  1  0.093  0.352  0.741  1.0
  Ba  Ba2  1  0.612  0.352  0.259  1.0
  Ba  Ba3  1  0.388  0.648  0.741  1.0
  Ba  Ba4  1  0.644  0.144  0.500  1.0
  Ba  Ba5  1  0.356  0.856  0.500  1.0
  Mg  Mg6  1  0.782  0.782  1.000  1.0
  Mg  Mg7  1  0.218  0.218  0.000  1.0
  Mg  Mg8  1  0.258  0.000  0.258  1.0
  Mg  Mg9  1  0.742  1.000  0.742  1.0
  Mg  Mg10  1  1.000  0.254  0.254  1.0
  Mg  Mg11  1  0.000  0.746  0.746  1.0
  Mg  Mg12  1  0.500  0.500  1.000  1.0
  H  H13  1  0.867  0.985  0.342  1.0
  H  H14  1  0.133  0.476  0.119  1.0
  H  H15  1  0.357  0.015  0.881  1.0
  H  H16  1  0.643  0.524  0.658  1.0
  H  H17  1  0.133  0.015  0.658  1.0
  H  H18  1  0.867  0.524  0.881  1.0
  H  H19  1  0.643  0.985  0.119  1.0
  H  H20  1  0.357  0.476  0.342  1.0
  H  H21  1  0.385  0.250  0.635  1.0
  H  H22  1  0.615  0.250  0.864  1.0
  H  H23  1  0.385  0.750  0.136  1.0
  H  H24  1  0.615  0.750  0.365  1.0
  H  H25  1  0.162  0.264  0.426  1.0
  H  H26  1  0.838  0.264  0.102  1.0
  H  H27  1  0.162  0.736  0.898  1.0
  H  H28  1  0.838  0.736  0.574  1.0
  H  H29  1  0.148  0.873  0.275  1.0
  H  H30  1  0.852  0.127  0.725  1.0
  H  H31  1  0.402  0.127  0.275  1.0
  H  H32  1  0.598  0.873  0.725  1.0
  H  H33  1  0.911  0.411  0.500  1.0
  H  H34  1  0.089  0.589  0.500  1.0
  H  H35  1  0.913  0.913  0.000  1.0
  H  H36  1  0.087  0.087  1.000  1.0
  H  H37  1  0.629  0.629  0.000  1.0
  H  H38  1  0.371  0.371  1.000  1.0
[/CIF]
.