The compound described by Tb4H9 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a distorted body-centered cubic geometry to two equivalent H(2) and eight equivalent H(1) atoms. In the second Tb site, Tb(2) is bonded in a distorted body-centered cubic geometry to one H(2) and eight equivalent H(1) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Tb(1) and two equivalent Tb(2) atoms to form HTb4 tetrahedra that share corners with three equivalent H(2)Tb6 octahedra, corners with sixteen equivalent H(1)Tb4 tetrahedra, edges with six equivalent H(1)Tb4 tetrahedra, and  a faceface with one H(2)Tb6 octahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the second H site, H(2) is bonded to two equivalent Tb(2) and four equivalent Tb(1) atoms to form HTb6 octahedra that share corners with four equivalent H(2)Tb6 octahedra, corners with twenty-four equivalent H(1)Tb4 tetrahedra, and faces with eight equivalent H(1)Tb4 tetrahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Tb4H9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.386
_cell_length_b   6.386
_cell_length_c   6.386
_cell_angle_alpha   131.974
_cell_angle_beta   131.974
_cell_angle_gamma   70.270
_symmetry_Int_Tables_number   1
_cell_volume   141.065
_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
  Tb  Tb0  1  0.500  0.000  0.500  1.0
  Tb  Tb1  1  0.000  0.500  0.500  1.0
  Tb  Tb2  1  0.748  0.748  0.000  1.0
  Tb  Tb3  1  0.252  0.252  0.000  1.0
  H  H4  1  0.885  0.370  0.000  1.0
  H  H5  1  0.370  0.885  0.000  1.0
  H  H6  1  0.630  0.115  0.000  1.0
  H  H7  1  0.115  0.115  0.485  1.0
  H  H8  1  0.370  0.370  0.485  1.0
  H  H9  1  0.500  0.500  0.000  1.0
  H  H10  1  0.115  0.630  0.000  1.0
  H  H11  1  0.630  0.630  0.515  1.0
  H  H12  1  0.885  0.885  0.515  1.0
[/CIF]
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The compound described by Tb4H9 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a distorted body-centered cubic geometry to two equivalent H(2) and eight equivalent H(1) atoms. In the second Tb site, Tb(2) is bonded in a distorted body-centered cubic geometry to one H(2) and eight equivalent H(1) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded to two equivalent Tb(1) and two equivalent Tb(2) atoms to form HTb4 tetrahedra that share corners with three equivalent H(2)Tb6 octahedra, corners with sixteen equivalent H(1)Tb4 tetrahedra, edges with six equivalent H(1)Tb4 tetrahedra, and  a faceface with one H(2)Tb6 octahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the second H site, H(2) is bonded to two equivalent Tb(2) and four equivalent Tb(1) atoms to form HTb6 octahedra that share corners with four equivalent H(2)Tb6 octahedra, corners with twenty-four equivalent H(1)Tb4 tetrahedra, and faces with eight equivalent H(1)Tb4 tetrahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Tb4H9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.386
_cell_length_b   6.386
_cell_length_c   6.386
_cell_angle_alpha   131.974
_cell_angle_beta   131.974
_cell_angle_gamma   70.270
_symmetry_Int_Tables_number   1
_cell_volume   141.065
_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
  Tb  Tb0  1  0.500  0.000  0.500  1.0
  Tb  Tb1  1  0.000  0.500  0.500  1.0
  Tb  Tb2  1  0.748  0.748  0.000  1.0
  Tb  Tb3  1  0.252  0.252  0.000  1.0
  H  H4  1  0.885  0.370  0.000  1.0
  H  H5  1  0.370  0.885  0.000  1.0
  H  H6  1  0.630  0.115  0.000  1.0
  H  H7  1  0.115  0.115  0.485  1.0
  H  H8  1  0.370  0.370  0.485  1.0
  H  H9  1  0.500  0.500  0.000  1.0
  H  H10  1  0.115  0.630  0.000  1.0
  H  H11  1  0.630  0.630  0.515  1.0
  H  H12  1  0.885  0.885  0.515  1.0
[/CIF]
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