data_BeCr2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.02
_cell_length_b   3.02
_cell_length_c   5.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeCr2Se
_chemical_formula_sum   'Be1 Cr2 Se1'
_cell_volume   47.18
_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  0.01  1.0
  Cr  Cr1  1  0.51  0.51  0.06  1.0
  Cr  Cr2  1  0.0  0.0  0.26  1.0
  Se  Se3  1  0.51  0.51  0.6  1.0

data_BeCr2Se
_symmetry_space_group_name_H-M   P4mm
_cell_length_a   3.02
_cell_length_b   3.02
_cell_length_c   5.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   99
_chemical_formula_structural   BeCr2Se
_chemical_formula_sum   'Be1 Cr2 Se1'
_cell_volume   47.18
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x, z'
  3  '-x, -y, z'
  4  'y, -x, z'
  5  '-x, y, z'
  6  'y, x, z'
  7  'x, -y, z'
  8  '-y, -x, 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  0.01  1.0
  Cr  Cr1  1  0.0  0.0  0.26  1.0
  Cr  Cr2  1  0.5  0.5  0.06  1.0
  Se  Se3  1  0.5  0.5  0.6  1.0

Be Cr Cr Se
BeCr2Se crystallizes in the monoclinic Cm space group. Be(1) is bonded in a distorted single-bond geometry to one Cr(2) and four equivalent Cr(1) atoms. The Be(1)-Cr(2) bond length is 1.31 Å. There are a spread of Be(1)-Cr(1) bond distances ranging from 2.11-2.20 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 10-coordinate geometry to four equivalent Be(1), four equivalent Cr(2), and two equivalent Se(1) atoms. There are a spread of Cr(1)-Cr(2) bond distances ranging from 2.33-2.41 Å. There is one shorter (2.36 Å) and one longer (2.81 Å) Cr(1)-Se(1) bond length. In the second Cr site, Cr(2) is bonded in a single-bond geometry to one Be(1), four equivalent Cr(1), and four equivalent Se(1) atoms. There are a spread of Cr(2)-Se(1) bond distances ranging from 2.74-2.81 Å. Se(1) is bonded in a 6-coordinate geometry to two equivalent Cr(1) and four equivalent Cr(2) atoms.