data_BeSi2Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.38
_cell_length_b   4.38
_cell_length_c   4.38
_cell_angle_alpha   131.99
_cell_angle_beta   131.99
_cell_angle_gamma   70.24
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeSi2Ni
_chemical_formula_sum   'Be1 Si2 Ni1'
_cell_volume   45.45
_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
  Si  Si2  1  0.0  0.78  0.79  1.0
  Si  Si3  1  0.78  0.0  0.79  1.0
  Ni  Ni1  1  0.0  0.0  0.58  1.0

data_BeSi2Ni
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.04
_cell_length_b   5.04
_cell_length_c   4.38
_cell_angle_alpha   90.0
_cell_angle_beta   125.12
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BeSi2Ni
_chemical_formula_sum   'Be2 Si4 Ni2'
_cell_volume   90.89
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.0  1.0
  Si  Si1  4  0.11  0.11  0.01  1.0
  Ni  Ni2  2  0.0  0.0  0.58  1.0

Be Si Si Ni
BeNiSi2 crystallizes in the monoclinic Cm space group. Be(1) is bonded in an L-shaped geometry to two equivalent Ni(1) and two equivalent Si(1) atoms. There is one shorter (1.83 Å) and one longer (2.55 Å) Be(1)-Ni(1) bond length. Both Be(1)-Si(1) bond lengths are 0.76 Å. Ni(1) is bonded in a 6-coordinate geometry to two equivalent Be(1) and four equivalent Si(1) atoms. There are two shorter (1.71 Å) and two longer (2.89 Å) Ni(1)-Si(1) bond lengths. Si(1) is bonded in a single-bond geometry to one Be(1) and two equivalent Ni(1) atoms.