The structure described by RbK2MgTbV2O8 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the monoclinic Cm space group. Rb(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(6) atoms. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Mg(1), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded in a 5-coordinate geometry to one K(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. Tb(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form TbO6 octahedra that share corners with three equivalent V(1)O4 tetrahedra. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(6), 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 20-51°. In the second V site, V(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Rb(1), one K(1), one K(2), 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(2), one Tb(1), and one V(1) atom. In the third O site, O(3) is bonded to one Rb(1), two equivalent K(1), one Mg(1), one Tb(1), and one V(2) atom to form distorted corner-sharing OK2RbTbMgV octahedra. The corner-sharing octahedral tilt angles are 4°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Tb(1), and one V(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Rb(1), one K(2), and one V(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Rb(1), one K(1), one K(2), and one V(1) atom. is represented by the CIF card [CIF]
data_K2RbTbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.241
_cell_length_b   5.827
_cell_length_c   8.286
_cell_angle_alpha   90.000
_cell_angle_beta   89.905
_cell_angle_gamma   117.829
_symmetry_Int_Tables_number   1
_cell_volume   266.482
_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  0.717  0.358  0.800  1.0
  K  K1  1  0.162  0.581  0.276  1.0
  Rb  Rb2  1  0.887  0.944  0.463  1.0
  Tb  Tb3  1  0.064  0.032  0.992  1.0
  Mg  Mg4  1  0.553  0.777  0.030  1.0
  V  V5  1  0.614  0.307  0.240  1.0
  V  V6  1  0.393  0.697  0.745  1.0
  O  O7  1  0.755  0.125  0.126  1.0
  O  O8  1  0.755  0.630  0.126  1.0
  O  O9  1  0.285  0.143  0.217  1.0
  O  O10  1  0.729  0.865  0.810  1.0
  O  O11  1  0.298  0.420  0.889  1.0
  O  O12  1  0.298  0.878  0.889  1.0
  O  O13  1  0.367  0.684  0.541  1.0
  O  O14  1  0.744  0.372  0.431  1.0
[/CIF]
.
The structure described by RbK2MgTbV2O8 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the monoclinic Cm space group. Rb(1) is bonded in a 7-coordinate geometry to one O(2), one O(3), one O(5), two equivalent O(1), and two equivalent O(6) atoms. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Mg(1), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded in a 5-coordinate geometry to one K(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. Tb(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form TbO6 octahedra that share corners with three equivalent V(1)O4 tetrahedra. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(6), 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 20-51°. In the second V site, V(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Rb(1), one K(1), one K(2), 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(2), one Tb(1), and one V(1) atom. In the third O site, O(3) is bonded to one Rb(1), two equivalent K(1), one Mg(1), one Tb(1), and one V(2) atom to form distorted corner-sharing OK2RbTbMgV octahedra. The corner-sharing octahedral tilt angles are 4°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one K(1), one Mg(1), one Tb(1), and one V(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Rb(1), one K(2), and one V(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Rb(1), one K(1), one K(2), and one V(1) atom. is represented by the CIF card [CIF]
data_K2RbTbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.241
_cell_length_b   5.827
_cell_length_c   8.286
_cell_angle_alpha   90.000
_cell_angle_beta   89.905
_cell_angle_gamma   117.829
_symmetry_Int_Tables_number   1
_cell_volume   266.482
_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  0.717  0.358  0.800  1.0
  K  K1  1  0.162  0.581  0.276  1.0
  Rb  Rb2  1  0.887  0.944  0.463  1.0
  Tb  Tb3  1  0.064  0.032  0.992  1.0
  Mg  Mg4  1  0.553  0.777  0.030  1.0
  V  V5  1  0.614  0.307  0.240  1.0
  V  V6  1  0.393  0.697  0.745  1.0
  O  O7  1  0.755  0.125  0.126  1.0
  O  O8  1  0.755  0.630  0.126  1.0
  O  O9  1  0.285  0.143  0.217  1.0
  O  O10  1  0.729  0.865  0.810  1.0
  O  O11  1  0.298  0.420  0.889  1.0
  O  O12  1  0.298  0.878  0.889  1.0
  O  O13  1  0.367  0.684  0.541  1.0
  O  O14  1  0.744  0.372  0.431  1.0
[/CIF]
.