The compound described by RbK2MgTbV2O8 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded in a distorted linear geometry to two equivalent O(2) atoms. K(1) is bonded in a 1-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. Tb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TbO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with three equivalent Tb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-27°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Tb(1), and one V(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent K(1), one Tb(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted linear geometry to one K(1) and one V(1) atom. is represented by the CIF file [CIF]
data_K2RbTbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.199
_cell_length_b   6.221
_cell_length_c   8.383
_cell_angle_alpha   93.475
_cell_angle_beta   90.000
_cell_angle_gamma   119.884
_symmetry_Int_Tables_number   1
_cell_volume   279.588
_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  K0  1  0.702  0.403  0.747  1.0
  K  K1  1  0.298  0.597  0.253  1.0
  Rb  Rb2  1  0.000  0.000  0.500  1.0
  Tb  Tb3  1  0.000  0.000  0.000  1.0
  Mg  Mg4  1  0.500  0.000  0.000  1.0
  V  V5  1  0.694  0.387  0.245  1.0
  V  V6  1  0.306  0.613  0.755  1.0
  O  O7  1  0.815  0.191  0.133  1.0
  O  O8  1  0.850  0.700  0.188  1.0
  O  O9  1  0.377  0.191  0.133  1.0
  O  O10  1  0.623  0.809  0.867  1.0
  O  O11  1  0.150  0.300  0.812  1.0
  O  O12  1  0.185  0.809  0.867  1.0
  O  O13  1  0.326  0.652  0.554  1.0
  O  O14  1  0.674  0.348  0.446  1.0
[/CIF]
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The compound described by RbK2MgTbV2O8 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded in a distorted linear geometry to two equivalent O(2) atoms. K(1) is bonded in a 1-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. Tb(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TbO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with three equivalent Tb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-27°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Tb(1), and one V(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent K(1), one Tb(1), and one V(1) atom. In the third O site, O(3) is bonded in a distorted linear geometry to one K(1) and one V(1) atom. is represented by the CIF file [CIF]
data_K2RbTbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.199
_cell_length_b   6.221
_cell_length_c   8.383
_cell_angle_alpha   93.475
_cell_angle_beta   90.000
_cell_angle_gamma   119.884
_symmetry_Int_Tables_number   1
_cell_volume   279.588
_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  K0  1  0.702  0.403  0.747  1.0
  K  K1  1  0.298  0.597  0.253  1.0
  Rb  Rb2  1  0.000  0.000  0.500  1.0
  Tb  Tb3  1  0.000  0.000  0.000  1.0
  Mg  Mg4  1  0.500  0.000  0.000  1.0
  V  V5  1  0.694  0.387  0.245  1.0
  V  V6  1  0.306  0.613  0.755  1.0
  O  O7  1  0.815  0.191  0.133  1.0
  O  O8  1  0.850  0.700  0.188  1.0
  O  O9  1  0.377  0.191  0.133  1.0
  O  O10  1  0.623  0.809  0.867  1.0
  O  O11  1  0.150  0.300  0.812  1.0
  O  O12  1  0.185  0.809  0.867  1.0
  O  O13  1  0.326  0.652  0.554  1.0
  O  O14  1  0.674  0.348  0.446  1.0
[/CIF]
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