data_BeCoNi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.55
_cell_length_b   3.55
_cell_length_c   3.55
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeCoNi
_chemical_formula_sum   'Be1 Co1 Ni1'
_cell_volume   31.64
_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
  Be  Be0  1  0.0  0.0  0.0  1.0
  Co  Co1  1  0.26  0.26  0.26  1.0
  Ni  Ni2  1  0.77  0.77  0.77  1.0

data_BeCoNi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.55
_cell_length_b   3.55
_cell_length_c   8.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BeCoNi
_chemical_formula_sum   'Be3 Co3 Ni3'
_cell_volume   94.92
_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
  Be  Be0  3  0.0  0.0  0.0  1.0
  Co  Co1  3  0.0  0.0  0.74  1.0
  Ni  Ni2  3  0.0  0.0  0.23  1.0

Be Co Ni
Be Co Ni 0 2 - - - 0 2 - - o 0 2 o - - 0 2 - o - 0 1 - o o 0 1 o - o 0 1 o o - 0 1 o o o 1 2 - - o 1 2 - o - 1 2 - o o 1 2 o - - 1 2 o - o 1 2 o o - 
BeCoNi is half-Heusler structured and crystallizes in the trigonal R3m space group. Be(1) is bonded in a body-centered cubic geometry to four equivalent Co(1) and four equivalent Ni(1) atoms. There are three shorter (2.16 Å) and one longer (2.22 Å) Be(1)-Co(1) bond length. There is one shorter (2.04 Å) and three longer (2.22 Å) Be(1)-Ni(1) bond lengths. Co(1) is bonded to four equivalent Be(1) atoms to form distorted CoBe4 tetrahedra that share corners with four equivalent Ni(1)Be4 tetrahedra, corners with twelve equivalent Co(1)Be4 tetrahedra, and edges with six equivalent Ni(1)Be4 tetrahedra. Ni(1) is bonded to four equivalent Be(1) atoms to form distorted NiBe4 tetrahedra that share corners with four equivalent Co(1)Be4 tetrahedra, corners with twelve equivalent Ni(1)Be4 tetrahedra, and edges with six equivalent Co(1)Be4 tetrahedra.