The crystal structure described by Rb3MgTbV2O8 crystallizes in the triclinic P1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(6), and one O(8) atom. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(5), and two equivalent O(7) atoms. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one V(2)O4 tetrahedra,  an edgeedge with one V(1)O4 tetrahedra, and  an edgeedge with one V(2)O4 tetrahedra. Tb(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form VO4 tetrahedra that share  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second V site, V(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one V(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one V(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Tb(1), and one V(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), 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 two equivalent Rb(2), one Mg(1), one Tb(1), and one V(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Rb(1), one Mg(1), one Tb(1), and one V(2) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Rb(3), two equivalent Rb(2), one Tb(1), and one V(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Rb(3), one Mg(1), and one V(2) atom. is represented by the CIF file [CIF]
data_Rb3TbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.509
_cell_length_b   5.967
_cell_length_c   8.976
_cell_angle_alpha   95.956
_cell_angle_beta   84.801
_cell_angle_gamma   126.086
_symmetry_Int_Tables_number   1
_cell_volume   280.006
_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
  Rb  Rb0  1  0.590  0.342  0.186  1.0
  Rb  Rb1  1  0.315  0.615  0.771  1.0
  Rb  Rb2  1  0.928  0.012  0.999  1.0
  Tb  Tb3  1  0.047  0.981  0.525  1.0
  Mg  Mg4  1  0.906  0.356  0.448  1.0
  V  V5  1  0.644  0.290  0.728  1.0
  V  V6  1  0.370  0.694  0.279  1.0
  O  O7  1  0.772  0.436  0.902  1.0
  O  O8  1  0.352  0.589  0.089  1.0
  O  O9  1  0.764  0.537  0.579  1.0
  O  O10  1  0.233  0.388  0.404  1.0
  O  O11  1  0.822  0.138  0.643  1.0
  O  O12  1  0.103  0.730  0.339  1.0
  O  O13  1  0.298  0.080  0.709  1.0
  O  O14  1  0.681  0.000  0.323  1.0
[/CIF]
.
The crystal structure described by Rb3MgTbV2O8 crystallizes in the triclinic P1 space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(6), and one O(8) atom. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(5), and two equivalent O(7) atoms. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one O(7), one O(8), two equivalent O(1), and two equivalent O(2) atoms. Mg(1) is bonded to one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one V(2)O4 tetrahedra,  an edgeedge with one V(1)O4 tetrahedra, and  an edgeedge with one V(2)O4 tetrahedra. Tb(1) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form VO4 tetrahedra that share  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second V site, V(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form VO4 tetrahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and  an edgeedge with one Mg(1)O5 trigonal bipyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one V(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one V(2) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Tb(1), and one V(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), 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 two equivalent Rb(2), one Mg(1), one Tb(1), and one V(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Rb(1), one Mg(1), one Tb(1), and one V(2) atom. In the seventh O site, O(7) is bonded in a 5-coordinate geometry to one Rb(3), two equivalent Rb(2), one Tb(1), and one V(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Rb(3), one Mg(1), and one V(2) atom. is represented by the CIF file [CIF]
data_Rb3TbMgV2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.509
_cell_length_b   5.967
_cell_length_c   8.976
_cell_angle_alpha   95.956
_cell_angle_beta   84.801
_cell_angle_gamma   126.086
_symmetry_Int_Tables_number   1
_cell_volume   280.006
_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
  Rb  Rb0  1  0.590  0.342  0.186  1.0
  Rb  Rb1  1  0.315  0.615  0.771  1.0
  Rb  Rb2  1  0.928  0.012  0.999  1.0
  Tb  Tb3  1  0.047  0.981  0.525  1.0
  Mg  Mg4  1  0.906  0.356  0.448  1.0
  V  V5  1  0.644  0.290  0.728  1.0
  V  V6  1  0.370  0.694  0.279  1.0
  O  O7  1  0.772  0.436  0.902  1.0
  O  O8  1  0.352  0.589  0.089  1.0
  O  O9  1  0.764  0.537  0.579  1.0
  O  O10  1  0.233  0.388  0.404  1.0
  O  O11  1  0.822  0.138  0.643  1.0
  O  O12  1  0.103  0.730  0.339  1.0
  O  O13  1  0.298  0.080  0.709  1.0
  O  O14  1  0.681  0.000  0.323  1.0
[/CIF]
.