data_LuH2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.53
_cell_length_b   3.53
_cell_length_c   3.53
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LuH2
_chemical_formula_sum   'Lu1 H2'
_cell_volume   31.02
_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
  Lu  Lu2  1  0.0  0.0  0.0  1.0
  H  H0  1  0.25  0.25  0.25  1.0
  H  H1  1  0.74  0.74  0.74  1.0

data_LuH2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.53
_cell_length_b   3.53
_cell_length_c   8.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   LuH2
_chemical_formula_sum   'Lu3 H6'
_cell_volume   93.05
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Lu  Lu0  3  0.0  0.0  0.0  1.0
  H  H1  3  0.0  0.0  0.26  1.0
  H  H2  3  0.0  0.0  0.75  1.0

Lu H H
LuH2 is Fluorite structured and crystallizes in the trigonal R3m space group. Lu(1) is bonded in a body-centered cubic geometry to four equivalent H(1) and four equivalent H(2) atoms. There is one shorter (2.13 Å) and three longer (2.17 Å) Lu(1)-H(1) bond lengths. There are three shorter (2.13 Å) and one longer (2.24 Å) Lu(1)-H(2) bond length. There are two inequivalent H sites. In the first H site, H(1) is bonded to four equivalent Lu(1) atoms to form a mixture of corner and edge-sharing HLu4 tetrahedra. In the second H site, H(2) is bonded to four equivalent Lu(1) atoms to form a mixture of corner and edge-sharing HLu4 tetrahedra.