The material described by K2B2Se7 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 9-coordinate geometry to one Se(1), two equivalent Se(3), three equivalent Se(2), and three equivalent Se(4) atoms. B(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing BSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted water-like geometry to two equivalent K(1) and two equivalent B(1) atoms. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to three equivalent K(1), one B(1), and one Se(3) atom. In the third Se site, Se(3) is bonded in a distorted single-bond geometry to two equivalent K(1), one B(1), and one Se(2) atom. In the fourth Se site, Se(4) is bonded in a distorted single-bond geometry to three equivalent K(1) and one B(1) atom. is represented by the CIF file [CIF]
data_K2B2Se7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.617
_cell_length_b   8.617
_cell_length_c   12.341
_cell_angle_alpha   61.954
_cell_angle_beta   61.954
_cell_angle_gamma   48.965
_symmetry_Int_Tables_number   1
_cell_volume   591.812
_cell_formula_units_Z   2
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  K0  1  0.675  0.119  0.023  1.0
  K  K1  1  0.881  0.325  0.477  1.0
  K  K2  1  0.325  0.881  0.977  1.0
  K  K3  1  0.119  0.675  0.523  1.0
  B  B4  1  0.842  0.391  0.152  1.0
  B  B5  1  0.609  0.158  0.348  1.0
  B  B6  1  0.158  0.609  0.848  1.0
  B  B7  1  0.391  0.842  0.652  1.0
  Se  Se8  1  0.540  0.460  0.250  1.0
  Se  Se9  1  0.460  0.540  0.750  1.0
  Se  Se10  1  0.172  0.568  0.021  1.0
  Se  Se11  1  0.432  0.828  0.479  1.0
  Se  Se12  1  0.828  0.432  0.979  1.0
  Se  Se13  1  0.568  0.172  0.521  1.0
  Se  Se14  1  0.848  0.612  0.168  1.0
  Se  Se15  1  0.388  0.152  0.332  1.0
  Se  Se16  1  0.152  0.388  0.832  1.0
  Se  Se17  1  0.612  0.848  0.668  1.0
  Se  Se18  1  0.071  0.094  0.230  1.0
  Se  Se19  1  0.906  0.929  0.270  1.0
  Se  Se20  1  0.929  0.906  0.770  1.0
  Se  Se21  1  0.094  0.071  0.730  1.0
[/CIF]
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The material described by K2B2Se7 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 9-coordinate geometry to one Se(1), two equivalent Se(3), three equivalent Se(2), and three equivalent Se(4) atoms. B(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing BSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted water-like geometry to two equivalent K(1) and two equivalent B(1) atoms. In the second Se site, Se(2) is bonded in a distorted single-bond geometry to three equivalent K(1), one B(1), and one Se(3) atom. In the third Se site, Se(3) is bonded in a distorted single-bond geometry to two equivalent K(1), one B(1), and one Se(2) atom. In the fourth Se site, Se(4) is bonded in a distorted single-bond geometry to three equivalent K(1) and one B(1) atom. is represented by the CIF file [CIF]
data_K2B2Se7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.617
_cell_length_b   8.617
_cell_length_c   12.341
_cell_angle_alpha   61.954
_cell_angle_beta   61.954
_cell_angle_gamma   48.965
_symmetry_Int_Tables_number   1
_cell_volume   591.812
_cell_formula_units_Z   2
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  K0  1  0.675  0.119  0.023  1.0
  K  K1  1  0.881  0.325  0.477  1.0
  K  K2  1  0.325  0.881  0.977  1.0
  K  K3  1  0.119  0.675  0.523  1.0
  B  B4  1  0.842  0.391  0.152  1.0
  B  B5  1  0.609  0.158  0.348  1.0
  B  B6  1  0.158  0.609  0.848  1.0
  B  B7  1  0.391  0.842  0.652  1.0
  Se  Se8  1  0.540  0.460  0.250  1.0
  Se  Se9  1  0.460  0.540  0.750  1.0
  Se  Se10  1  0.172  0.568  0.021  1.0
  Se  Se11  1  0.432  0.828  0.479  1.0
  Se  Se12  1  0.828  0.432  0.979  1.0
  Se  Se13  1  0.568  0.172  0.521  1.0
  Se  Se14  1  0.848  0.612  0.168  1.0
  Se  Se15  1  0.388  0.152  0.332  1.0
  Se  Se16  1  0.152  0.388  0.832  1.0
  Se  Se17  1  0.612  0.848  0.668  1.0
  Se  Se18  1  0.071  0.094  0.230  1.0
  Se  Se19  1  0.906  0.929  0.270  1.0
  Se  Se20  1  0.929  0.906  0.770  1.0
  Se  Se21  1  0.094  0.071  0.730  1.0
[/CIF]
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