data_KBeNb2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.08
_cell_length_b   11.08
_cell_length_c   11.08
_cell_angle_alpha   14.94
_cell_angle_beta   14.94
_cell_angle_gamma   14.94
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KBeNb2
_chemical_formula_sum   'K1 Be1 Nb2'
_cell_volume   78.73
_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
  K  K1  1  0.0  0.0  0.43  1.0
  Be  Be0  1  0.0  0.0  0.0  1.0
  Nb  Nb2  1  0.0  0.0  0.05  1.0
  Nb  Nb3  1  0.0  0.0  0.81  1.0

data_KBeNb2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.99
_cell_length_b   2.88
_cell_length_c   11.08
_cell_angle_alpha   90.0
_cell_angle_beta   98.63
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   KBeNb2
_chemical_formula_sum   'K2 Be2 Nb4'
_cell_volume   157.46
_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
  K  K0  2  0.0  0.0  0.57  1.0
  Be  Be1  2  0.0  0.0  0.0  1.0
  Nb  Nb2  2  0.0  0.0  0.19  1.0
  Nb  Nb3  2  0.0  0.0  0.95  1.0

K Be Nb Nb
KBeNb2 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to six K(1,1); one Nb(1); and one Nb(2) atom to form a mixture of edge and corner-sharing KK6Nb2 hexagonal bipyramids. All K(1)-K(1,1) bond lengths are 2.88 Å. The K(1)-Nb(1) bond length is 4.19 Å. The K(1)-Nb(2) bond length is 4.19 Å. In the second K site, K(1) is bonded to six K(1,1); one Nb(1); and one Nb(2) atom to form a mixture of edge and corner-sharing KK6Nb2 hexagonal bipyramids. Both K(1)-K(1) bond lengths are 2.88 Å. The K(1)-Nb(1) bond length is 4.19 Å. The K(1)-Nb(2) bond length is 4.19 Å. Be(1) is bonded in a single-bond geometry to one Nb(1) and one Nb(2) atom. The Be(1)-Nb(1) bond length is 0.58 Å. The Be(1)-Nb(2) bond length is 2.13 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a single-bond geometry to one K(1) and one Be(1) atom. In the second Nb site, Nb(2) is bonded in a distorted single-bond geometry to one K(1) and one Be(1) atom.