The crystal structure described by Gd2B4O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 10-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), two equivalent O(1), and two equivalent O(9) atoms. In the second Gd site, Gd(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), two equivalent O(3), and two equivalent O(8) atoms. There are four inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(4), one O(7), and one O(8) atom. In the second B site, B(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form corner-sharing BO4 tetrahedra. In the third B site, B(3) is bonded to one O(2), one O(4), one O(6), and one O(9) atom to form corner-sharing BO4 tetrahedra. In the fourth B site, B(4) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing BO4 tetrahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Gd(2), two equivalent Gd(1), and one B(2) atom to form distorted edge-sharing OGd3B tetrahedra. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one Gd(2), one B(2), and one B(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Gd(1), two equivalent Gd(2), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Gd(1), one Gd(2), one B(1), and one B(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Gd(1), one Gd(2), one B(2), and one B(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Gd(2), one B(3), and one B(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one B(1), and one B(4) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Gd(1), two equivalent Gd(2), and one B(1) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to two equivalent Gd(1), one B(3), and one B(4) atom. is represented by the CIF file [CIF]
data_Gd2B4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.185
_cell_length_b   6.459
_cell_length_c   7.509
_cell_angle_alpha   102.332
_cell_angle_beta   97.139
_cell_angle_gamma   102.574
_symmetry_Int_Tables_number   1
_cell_volume   281.407
_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
  Gd  Gd0  1  0.453  0.908  0.716  1.0
  Gd  Gd1  1  0.547  0.092  0.284  1.0
  Gd  Gd2  1  0.113  0.322  0.640  1.0
  Gd  Gd3  1  0.887  0.678  0.360  1.0
  B  B4  1  0.995  0.148  0.188  1.0
  B  B5  1  0.005  0.852  0.812  1.0
  B  B6  1  0.374  0.643  0.348  1.0
  B  B7  1  0.626  0.357  0.652  1.0
  B  B8  1  0.269  0.665  0.019  1.0
  B  B9  1  0.731  0.335  0.981  1.0
  B  B10  1  0.338  0.320  0.074  1.0
  B  B11  1  0.662  0.680  0.926  1.0
  O  O12  1  0.578  0.816  0.443  1.0
  O  O13  1  0.238  0.736  0.210  1.0
  O  O14  1  0.779  0.407  0.525  1.0
  O  O15  1  0.221  0.593  0.475  1.0
  O  O16  1  0.762  0.264  0.790  1.0
  O  O17  1  0.861  0.282  0.140  1.0
  O  O18  1  0.541  0.536  0.749  1.0
  O  O19  1  0.459  0.464  0.251  1.0
  O  O20  1  0.774  0.570  0.039  1.0
  O  O21  1  0.226  0.430  0.961  1.0
  O  O22  1  0.813  0.866  0.881  1.0
  O  O23  1  0.187  0.134  0.119  1.0
  O  O24  1  0.066  0.952  0.677  1.0
  O  O25  1  0.934  0.048  0.323  1.0
  O  O26  1  0.495  0.214  0.982  1.0
  O  O27  1  0.505  0.786  0.018  1.0
  O  O28  1  0.139  0.718  0.860  1.0
  O  O29  1  0.422  0.184  0.557  1.0
[/CIF]
.
The crystal structure described by Gd2B4O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 10-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), two equivalent O(1), and two equivalent O(9) atoms. In the second Gd site, Gd(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), two equivalent O(3), and two equivalent O(8) atoms. There are four inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(4), one O(7), and one O(8) atom. In the second B site, B(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form corner-sharing BO4 tetrahedra. In the third B site, B(3) is bonded to one O(2), one O(4), one O(6), and one O(9) atom to form corner-sharing BO4 tetrahedra. In the fourth B site, B(4) is bonded to one O(5), one O(6), one O(7), and one O(9) atom to form corner-sharing BO4 tetrahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded to one Gd(2), two equivalent Gd(1), and one B(2) atom to form distorted edge-sharing OGd3B tetrahedra. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one Gd(2), one B(2), and one B(3) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Gd(1), two equivalent Gd(2), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Gd(1), one Gd(2), one B(1), and one B(3) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Gd(1), one Gd(2), one B(2), and one B(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Gd(2), one B(3), and one B(4) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Gd(1), one B(1), and one B(4) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Gd(1), two equivalent Gd(2), and one B(1) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to two equivalent Gd(1), one B(3), and one B(4) atom. is represented by the CIF file [CIF]
data_Gd2B4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.185
_cell_length_b   6.459
_cell_length_c   7.509
_cell_angle_alpha   102.332
_cell_angle_beta   97.139
_cell_angle_gamma   102.574
_symmetry_Int_Tables_number   1
_cell_volume   281.407
_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
  Gd  Gd0  1  0.453  0.908  0.716  1.0
  Gd  Gd1  1  0.547  0.092  0.284  1.0
  Gd  Gd2  1  0.113  0.322  0.640  1.0
  Gd  Gd3  1  0.887  0.678  0.360  1.0
  B  B4  1  0.995  0.148  0.188  1.0
  B  B5  1  0.005  0.852  0.812  1.0
  B  B6  1  0.374  0.643  0.348  1.0
  B  B7  1  0.626  0.357  0.652  1.0
  B  B8  1  0.269  0.665  0.019  1.0
  B  B9  1  0.731  0.335  0.981  1.0
  B  B10  1  0.338  0.320  0.074  1.0
  B  B11  1  0.662  0.680  0.926  1.0
  O  O12  1  0.578  0.816  0.443  1.0
  O  O13  1  0.238  0.736  0.210  1.0
  O  O14  1  0.779  0.407  0.525  1.0
  O  O15  1  0.221  0.593  0.475  1.0
  O  O16  1  0.762  0.264  0.790  1.0
  O  O17  1  0.861  0.282  0.140  1.0
  O  O18  1  0.541  0.536  0.749  1.0
  O  O19  1  0.459  0.464  0.251  1.0
  O  O20  1  0.774  0.570  0.039  1.0
  O  O21  1  0.226  0.430  0.961  1.0
  O  O22  1  0.813  0.866  0.881  1.0
  O  O23  1  0.187  0.134  0.119  1.0
  O  O24  1  0.066  0.952  0.677  1.0
  O  O25  1  0.934  0.048  0.323  1.0
  O  O26  1  0.495  0.214  0.982  1.0
  O  O27  1  0.505  0.786  0.018  1.0
  O  O28  1  0.139  0.718  0.860  1.0
  O  O29  1  0.422  0.184  0.557  1.0
[/CIF]
.