The structure described by BeHf3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Be(1) is bonded to four equivalent Hf(2) and eight equivalent Hf(1) atoms to form BeHf12 cuboctahedra that share corners with four equivalent Be(1)Hf12 cuboctahedra, corners with eight equivalent Hf(2)Hf8Be4 cuboctahedra, edges with eight equivalent Be(1)Hf12 cuboctahedra, edges with sixteen equivalent Hf(1)Hf8Be4 cuboctahedra, faces with four equivalent Be(1)Hf12 cuboctahedra, faces with six equivalent Hf(2)Hf8Be4 cuboctahedra, and faces with eight equivalent Hf(1)Hf8Be4 cuboctahedra. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent Be(1), four equivalent Hf(1), and four equivalent Hf(2) atoms to form HfHf8Be4 cuboctahedra that share corners with twelve equivalent Hf(1)Hf8Be4 cuboctahedra, edges with eight equivalent Be(1)Hf12 cuboctahedra, edges with eight equivalent Hf(1)Hf8Be4 cuboctahedra, edges with eight equivalent Hf(2)Hf8Be4 cuboctahedra, faces with four equivalent Be(1)Hf12 cuboctahedra, faces with four equivalent Hf(2)Hf8Be4 cuboctahedra, and faces with ten equivalent Hf(1)Hf8Be4 cuboctahedra. In the second Hf site, Hf(2) is bonded to four equivalent Be(1) and eight equivalent Hf(1) atoms to form distorted HfHf8Be4 cuboctahedra that share corners with four equivalent Hf(2)Hf8Be4 cuboctahedra, corners with eight equivalent Be(1)Hf12 cuboctahedra, edges with eight equivalent Hf(2)Hf8Be4 cuboctahedra, edges with sixteen equivalent Hf(1)Hf8Be4 cuboctahedra, faces with four equivalent Hf(2)Hf8Be4 cuboctahedra, faces with six equivalent Be(1)Hf12 cuboctahedra, and faces with eight equivalent Hf(1)Hf8Be4 cuboctahedra. is represented by the CIF file [CIF]
data_Hf3Be
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.263
_cell_length_b   5.263
_cell_length_c   5.263
_cell_angle_alpha   133.160
_cell_angle_beta   133.160
_cell_angle_gamma   68.404
_symmetry_Int_Tables_number   1
_cell_volume   76.204
_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
  Hf  Hf0  1  0.750  0.250  0.500  1.0
  Hf  Hf1  1  0.250  0.750  0.500  1.0
  Hf  Hf2  1  0.500  0.500  0.000  1.0
  Be  Be3  1  0.000  0.000  0.000  1.0
[/CIF]
.
The structure described by BeHf3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Be(1) is bonded to four equivalent Hf(2) and eight equivalent Hf(1) atoms to form BeHf12 cuboctahedra that share corners with four equivalent Be(1)Hf12 cuboctahedra, corners with eight equivalent Hf(2)Hf8Be4 cuboctahedra, edges with eight equivalent Be(1)Hf12 cuboctahedra, edges with sixteen equivalent Hf(1)Hf8Be4 cuboctahedra, faces with four equivalent Be(1)Hf12 cuboctahedra, faces with six equivalent Hf(2)Hf8Be4 cuboctahedra, and faces with eight equivalent Hf(1)Hf8Be4 cuboctahedra. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent Be(1), four equivalent Hf(1), and four equivalent Hf(2) atoms to form HfHf8Be4 cuboctahedra that share corners with twelve equivalent Hf(1)Hf8Be4 cuboctahedra, edges with eight equivalent Be(1)Hf12 cuboctahedra, edges with eight equivalent Hf(1)Hf8Be4 cuboctahedra, edges with eight equivalent Hf(2)Hf8Be4 cuboctahedra, faces with four equivalent Be(1)Hf12 cuboctahedra, faces with four equivalent Hf(2)Hf8Be4 cuboctahedra, and faces with ten equivalent Hf(1)Hf8Be4 cuboctahedra. In the second Hf site, Hf(2) is bonded to four equivalent Be(1) and eight equivalent Hf(1) atoms to form distorted HfHf8Be4 cuboctahedra that share corners with four equivalent Hf(2)Hf8Be4 cuboctahedra, corners with eight equivalent Be(1)Hf12 cuboctahedra, edges with eight equivalent Hf(2)Hf8Be4 cuboctahedra, edges with sixteen equivalent Hf(1)Hf8Be4 cuboctahedra, faces with four equivalent Hf(2)Hf8Be4 cuboctahedra, faces with six equivalent Be(1)Hf12 cuboctahedra, and faces with eight equivalent Hf(1)Hf8Be4 cuboctahedra. is represented by the CIF file [CIF]
data_Hf3Be
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.263
_cell_length_b   5.263
_cell_length_c   5.263
_cell_angle_alpha   133.160
_cell_angle_beta   133.160
_cell_angle_gamma   68.404
_symmetry_Int_Tables_number   1
_cell_volume   76.204
_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
  Hf  Hf0  1  0.750  0.250  0.500  1.0
  Hf  Hf1  1  0.250  0.750  0.500  1.0
  Hf  Hf2  1  0.500  0.500  0.000  1.0
  Be  Be3  1  0.000  0.000  0.000  1.0
[/CIF]
.