The structure described by K2B4O7 crystallizes in the triclinic P-1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(6), two equivalent O(5), and two equivalent O(9) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(9), two equivalent O(10), and two equivalent O(4) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(4), one O(7), and two equivalent O(8) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one O(1), one O(14), one O(6), one O(7), and two equivalent O(13) atoms. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(10), one O(3), and one O(9) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(11), one O(14), and one O(6) atom. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(12), one O(4), and one O(8) atom. In the fourth B site, B(4) is bonded in a trigonal planar geometry to one O(13), one O(2), and one O(5) atom. In the fifth B site, B(5) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing BO4 tetrahedra. In the sixth B site, B(6) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing BO4 tetrahedra. In the seventh B site, B(7) is bonded to one O(1), one O(12), one O(13), and one O(14) atom to form corner-sharing BO4 tetrahedra. In the eighth B site, B(8) is bonded to one O(10), one O(11), one O(7), and one O(8) atom to form corner-sharing BO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one K(3), one K(4), one B(6), and one B(7) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one K(1), one K(2), one B(4), and one B(6) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one K(1), one K(2), one B(1), and one B(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(3), two equivalent K(2), one B(3), and one B(6) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one B(4), and one B(5) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(4), one B(2), and one B(5) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(3), one K(4), one B(5), and one B(8) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to two equivalent K(3), one B(3), and one B(8) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one K(2), two equivalent K(1), one B(1), and one B(5) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to two equivalent K(2), one B(1), and one B(8) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(2), and one B(8) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one K(3), one B(3), and one B(7) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to two equivalent K(4), one B(4), and one B(7) atom. In the fourteenth O site, O(14) is bonded in a 2-coordinate geometry to one K(4), one B(2), and one B(7) atom. is represented by the CIF file [CIF]
data_K2B4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.493
_cell_length_b   9.589
_cell_length_c   10.399
_cell_angle_alpha   89.421
_cell_angle_beta   102.619
_cell_angle_gamma   101.069
_symmetry_Int_Tables_number   1
_cell_volume   619.675
_cell_formula_units_Z   4
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  0.747  0.997  0.593  1.0
  K  K1  1  0.253  0.003  0.407  1.0
  K  K2  1  0.209  0.627  0.503  1.0
  K  K3  1  0.791  0.373  0.497  1.0
  K  K4  1  0.664  0.478  0.873  1.0
  K  K5  1  0.336  0.522  0.127  1.0
  K  K6  1  0.627  0.873  0.958  1.0
  K  K7  1  0.373  0.127  0.042  1.0
  B  B8  1  0.666  0.699  0.455  1.0
  B  B9  1  0.334  0.301  0.545  1.0
  B  B10  1  0.131  0.810  0.159  1.0
  B  B11  1  0.869  0.190  0.841  1.0
  B  B12  1  0.125  0.556  0.813  1.0
  B  B13  1  0.875  0.444  0.187  1.0
  B  B14  1  0.189  0.910  0.730  1.0
  B  B15  1  0.811  0.090  0.270  1.0
  B  B16  1  0.548  0.848  0.269  1.0
  B  B17  1  0.452  0.152  0.731  1.0
  B  B18  1  0.882  0.701  0.686  1.0
  B  B19  1  0.118  0.299  0.314  1.0
  B  B20  1  0.055  0.778  0.907  1.0
  B  B21  1  0.945  0.222  0.093  1.0
  B  B22  1  0.812  0.687  0.252  1.0
  B  B23  1  0.188  0.313  0.748  1.0
  O  O24  1  0.850  0.744  0.811  1.0
  O  O25  1  0.042  0.814  0.640  1.0
  O  O26  1  0.322  0.322  0.413  1.0
  O  O27  1  0.678  0.678  0.587  1.0
  O  O28  1  0.029  0.433  0.300  1.0
  O  O29  1  0.958  0.186  0.360  1.0
  O  O30  1  0.324  0.010  0.677  1.0
  O  O31  1  0.676  0.990  0.323  1.0
  O  O32  1  0.654  0.128  0.816  1.0
  O  O33  1  0.346  0.872  0.184  1.0
  O  O34  1  0.348  0.231  0.804  1.0
  O  O35  1  0.652  0.769  0.196  1.0
  O  O36  1  0.232  0.445  0.831  1.0
  O  O37  1  0.768  0.555  0.169  1.0
  O  O38  1  0.488  0.227  0.608  1.0
  O  O39  1  0.512  0.773  0.392  1.0
  O  O40  1  0.203  0.352  0.610  1.0
  O  O41  1  0.797  0.648  0.390  1.0
  O  O42  1  0.962  0.236  0.738  1.0
  O  O43  1  0.038  0.764  0.262  1.0
  O  O44  1  0.172  0.656  0.914  1.0
  O  O45  1  0.828  0.344  0.086  1.0
  O  O46  1  0.197  0.903  0.862  1.0
  O  O47  1  0.803  0.097  0.138  1.0
  O  O48  1  0.011  0.803  0.034  1.0
  O  O49  1  0.989  0.197  0.966  1.0
  O  O50  1  0.971  0.567  0.700  1.0
  O  O51  1  0.150  0.256  0.189  1.0
[/CIF]
.
The structure described by K2B4O7 crystallizes in the triclinic P-1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(6), two equivalent O(5), and two equivalent O(9) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(11), one O(2), one O(3), one O(9), two equivalent O(10), and two equivalent O(4) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(1), one O(12), one O(4), one O(7), and two equivalent O(8) atoms. In the fourth K site, K(4) is bonded in a 6-coordinate geometry to one O(1), one O(14), one O(6), one O(7), and two equivalent O(13) atoms. There are eight inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(10), one O(3), and one O(9) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(11), one O(14), and one O(6) atom. In the third B site, B(3) is bonded in a trigonal planar geometry to one O(12), one O(4), and one O(8) atom. In the fourth B site, B(4) is bonded in a trigonal planar geometry to one O(13), one O(2), and one O(5) atom. In the fifth B site, B(5) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing BO4 tetrahedra. In the sixth B site, B(6) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing BO4 tetrahedra. In the seventh B site, B(7) is bonded to one O(1), one O(12), one O(13), and one O(14) atom to form corner-sharing BO4 tetrahedra. In the eighth B site, B(8) is bonded to one O(10), one O(11), one O(7), and one O(8) atom to form corner-sharing BO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one K(3), one K(4), one B(6), and one B(7) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one K(1), one K(2), one B(4), and one B(6) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one K(1), one K(2), one B(1), and one B(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one K(3), two equivalent K(2), one B(3), and one B(6) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one B(4), and one B(5) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one K(1), one K(4), one B(2), and one B(5) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(3), one K(4), one B(5), and one B(8) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to two equivalent K(3), one B(3), and one B(8) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one K(2), two equivalent K(1), one B(1), and one B(5) atom. In the tenth O site, O(10) is bonded in a distorted bent 120 degrees geometry to two equivalent K(2), one B(1), and one B(8) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one B(2), and one B(8) atom. In the twelfth O site, O(12) is bonded in a distorted bent 120 degrees geometry to one K(3), one B(3), and one B(7) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 120 degrees geometry to two equivalent K(4), one B(4), and one B(7) atom. In the fourteenth O site, O(14) is bonded in a 2-coordinate geometry to one K(4), one B(2), and one B(7) atom. is represented by the CIF file [CIF]
data_K2B4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.493
_cell_length_b   9.589
_cell_length_c   10.399
_cell_angle_alpha   89.421
_cell_angle_beta   102.619
_cell_angle_gamma   101.069
_symmetry_Int_Tables_number   1
_cell_volume   619.675
_cell_formula_units_Z   4
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  0.747  0.997  0.593  1.0
  K  K1  1  0.253  0.003  0.407  1.0
  K  K2  1  0.209  0.627  0.503  1.0
  K  K3  1  0.791  0.373  0.497  1.0
  K  K4  1  0.664  0.478  0.873  1.0
  K  K5  1  0.336  0.522  0.127  1.0
  K  K6  1  0.627  0.873  0.958  1.0
  K  K7  1  0.373  0.127  0.042  1.0
  B  B8  1  0.666  0.699  0.455  1.0
  B  B9  1  0.334  0.301  0.545  1.0
  B  B10  1  0.131  0.810  0.159  1.0
  B  B11  1  0.869  0.190  0.841  1.0
  B  B12  1  0.125  0.556  0.813  1.0
  B  B13  1  0.875  0.444  0.187  1.0
  B  B14  1  0.189  0.910  0.730  1.0
  B  B15  1  0.811  0.090  0.270  1.0
  B  B16  1  0.548  0.848  0.269  1.0
  B  B17  1  0.452  0.152  0.731  1.0
  B  B18  1  0.882  0.701  0.686  1.0
  B  B19  1  0.118  0.299  0.314  1.0
  B  B20  1  0.055  0.778  0.907  1.0
  B  B21  1  0.945  0.222  0.093  1.0
  B  B22  1  0.812  0.687  0.252  1.0
  B  B23  1  0.188  0.313  0.748  1.0
  O  O24  1  0.850  0.744  0.811  1.0
  O  O25  1  0.042  0.814  0.640  1.0
  O  O26  1  0.322  0.322  0.413  1.0
  O  O27  1  0.678  0.678  0.587  1.0
  O  O28  1  0.029  0.433  0.300  1.0
  O  O29  1  0.958  0.186  0.360  1.0
  O  O30  1  0.324  0.010  0.677  1.0
  O  O31  1  0.676  0.990  0.323  1.0
  O  O32  1  0.654  0.128  0.816  1.0
  O  O33  1  0.346  0.872  0.184  1.0
  O  O34  1  0.348  0.231  0.804  1.0
  O  O35  1  0.652  0.769  0.196  1.0
  O  O36  1  0.232  0.445  0.831  1.0
  O  O37  1  0.768  0.555  0.169  1.0
  O  O38  1  0.488  0.227  0.608  1.0
  O  O39  1  0.512  0.773  0.392  1.0
  O  O40  1  0.203  0.352  0.610  1.0
  O  O41  1  0.797  0.648  0.390  1.0
  O  O42  1  0.962  0.236  0.738  1.0
  O  O43  1  0.038  0.764  0.262  1.0
  O  O44  1  0.172  0.656  0.914  1.0
  O  O45  1  0.828  0.344  0.086  1.0
  O  O46  1  0.197  0.903  0.862  1.0
  O  O47  1  0.803  0.097  0.138  1.0
  O  O48  1  0.011  0.803  0.034  1.0
  O  O49  1  0.989  0.197  0.966  1.0
  O  O50  1  0.971  0.567  0.700  1.0
  O  O51  1  0.150  0.256  0.189  1.0
[/CIF]
.