The material described by Dy2B4O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(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 Dy site, Dy(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 Dy(2), two equivalent Dy(1), and one B(2) atom to form distorted edge-sharing ODy3B tetrahedra. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Dy(1), one Dy(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 Dy(1), two equivalent Dy(2), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Dy(1), one Dy(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 Dy(1), one Dy(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 Dy(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 Dy(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 Dy(1), two equivalent Dy(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 Dy(1), one B(3), and one B(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Dy2B4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.136
_cell_length_b   6.396
_cell_length_c   7.462
_cell_angle_alpha   102.569
_cell_angle_beta   97.277
_cell_angle_gamma   102.452
_symmetry_Int_Tables_number   1
_cell_volume   274.410
_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
  Dy  Dy0  1  0.451  0.909  0.713  1.0
  Dy  Dy1  1  0.549  0.091  0.287  1.0
  Dy  Dy2  1  0.113  0.324  0.641  1.0
  Dy  Dy3  1  0.887  0.676  0.359  1.0
  B  B4  1  0.996  0.145  0.190  1.0
  B  B5  1  0.004  0.855  0.810  1.0
  B  B6  1  0.375  0.643  0.350  1.0
  B  B7  1  0.625  0.357  0.650  1.0
  B  B8  1  0.267  0.666  0.019  1.0
  B  B9  1  0.733  0.334  0.981  1.0
  B  B10  1  0.339  0.317  0.073  1.0
  B  B11  1  0.661  0.683  0.927  1.0
  O  O12  1  0.581  0.818  0.446  1.0
  O  O13  1  0.764  0.263  0.788  1.0
  O  O14  1  0.780  0.407  0.523  1.0
  O  O15  1  0.220  0.593  0.477  1.0
  O  O16  1  0.236  0.737  0.212  1.0
  O  O17  1  0.863  0.283  0.143  1.0
  O  O18  1  0.538  0.537  0.748  1.0
  O  O19  1  0.462  0.463  0.252  1.0
  O  O20  1  0.775  0.573  0.041  1.0
  O  O21  1  0.225  0.427  0.959  1.0
  O  O22  1  0.811  0.870  0.879  1.0
  O  O23  1  0.189  0.130  0.121  1.0
  O  O24  1  0.069  0.956  0.675  1.0
  O  O25  1  0.931  0.044  0.325  1.0
  O  O26  1  0.496  0.210  0.979  1.0
  O  O27  1  0.504  0.790  0.021  1.0
  O  O28  1  0.137  0.717  0.857  1.0
  O  O29  1  0.419  0.182  0.554  1.0
[/CIF]
.
The material described by Dy2B4O9 crystallizes in the triclinic P-1 space group. There are two inequivalent Dy sites. In the first Dy site, Dy(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 Dy site, Dy(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 Dy(2), two equivalent Dy(1), and one B(2) atom to form distorted edge-sharing ODy3B tetrahedra. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Dy(1), one Dy(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 Dy(1), two equivalent Dy(2), and one B(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Dy(1), one Dy(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 Dy(1), one Dy(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 Dy(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 Dy(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 Dy(1), two equivalent Dy(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 Dy(1), one B(3), and one B(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Dy2B4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.136
_cell_length_b   6.396
_cell_length_c   7.462
_cell_angle_alpha   102.569
_cell_angle_beta   97.277
_cell_angle_gamma   102.452
_symmetry_Int_Tables_number   1
_cell_volume   274.410
_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
  Dy  Dy0  1  0.451  0.909  0.713  1.0
  Dy  Dy1  1  0.549  0.091  0.287  1.0
  Dy  Dy2  1  0.113  0.324  0.641  1.0
  Dy  Dy3  1  0.887  0.676  0.359  1.0
  B  B4  1  0.996  0.145  0.190  1.0
  B  B5  1  0.004  0.855  0.810  1.0
  B  B6  1  0.375  0.643  0.350  1.0
  B  B7  1  0.625  0.357  0.650  1.0
  B  B8  1  0.267  0.666  0.019  1.0
  B  B9  1  0.733  0.334  0.981  1.0
  B  B10  1  0.339  0.317  0.073  1.0
  B  B11  1  0.661  0.683  0.927  1.0
  O  O12  1  0.581  0.818  0.446  1.0
  O  O13  1  0.764  0.263  0.788  1.0
  O  O14  1  0.780  0.407  0.523  1.0
  O  O15  1  0.220  0.593  0.477  1.0
  O  O16  1  0.236  0.737  0.212  1.0
  O  O17  1  0.863  0.283  0.143  1.0
  O  O18  1  0.538  0.537  0.748  1.0
  O  O19  1  0.462  0.463  0.252  1.0
  O  O20  1  0.775  0.573  0.041  1.0
  O  O21  1  0.225  0.427  0.959  1.0
  O  O22  1  0.811  0.870  0.879  1.0
  O  O23  1  0.189  0.130  0.121  1.0
  O  O24  1  0.069  0.956  0.675  1.0
  O  O25  1  0.931  0.044  0.325  1.0
  O  O26  1  0.496  0.210  0.979  1.0
  O  O27  1  0.504  0.790  0.021  1.0
  O  O28  1  0.137  0.717  0.857  1.0
  O  O29  1  0.419  0.182  0.554  1.0
[/CIF]
.