The compound described by Mg3V2(BiO6)2 crystallizes in the monoclinic Pm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(5), and two equivalent O(7) atoms to form MgO5 square pyramids that share  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, and corners with two equivalent Mg(3)O5 trigonal bipyramids. In the second Mg site, Mg(2) is bonded to one O(2), two equivalent O(6), and two equivalent O(8) atoms to form MgO5 square pyramids that share  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, and  an edgeedge with one Mg(3)O5 trigonal bipyramid. In the third Mg site, Mg(3) is bonded to one O(3), two equivalent O(6), and two equivalent O(7) atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, and  an edgeedge with one Mg(2)O5 square pyramid. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(4), and two equivalent O(6) atoms to form VO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Mg(2)O5 square pyramids, and corners with two equivalent Mg(3)O5 trigonal bipyramids. In the second V site, V(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form VO4 tetrahedra that share  a cornercorner with one Mg(2)O5 square pyramid, corners with two equivalent Mg(1)O5 square pyramids, and  a cornercorner with one Mg(3)O5 trigonal bipyramid. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to two equivalent O(7) and two equivalent O(8) atoms. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to two equivalent O(7) and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one V(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(2) and one V(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mg(3) and one V(2) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one V(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one V(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(2), one Mg(3), and one V(1) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Mg(3), one Bi(1), and one Bi(2) atom to form edge-sharing OMg2Bi2 tetrahedra. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Mg(2), one Bi(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_Mg3V2(BiO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.527
_cell_length_b   7.581
_cell_length_c   7.416
_cell_angle_alpha   114.968
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   281.688
_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
  Mg  Mg0  1  0.750  0.100  0.273  1.0
  Mg  Mg1  1  0.250  0.900  0.726  1.0
  Mg  Mg2  1  0.250  0.285  0.107  1.0
  V  V3  1  0.750  0.194  0.800  1.0
  V  V4  1  0.250  0.803  0.201  1.0
  Bi  Bi5  1  0.250  0.410  0.595  1.0
  Bi  Bi6  1  0.750  0.586  0.409  1.0
  O  O7  1  0.750  0.102  0.544  1.0
  O  O8  1  0.250  0.896  0.455  1.0
  O  O9  1  0.250  0.548  0.098  1.0
  O  O10  1  0.750  0.437  0.898  1.0
  O  O11  1  0.003  0.897  0.126  1.0
  O  O12  1  0.485  0.118  0.887  1.0
  O  O13  1  0.015  0.118  0.887  1.0
  O  O14  1  0.497  0.897  0.126  1.0
  O  O15  1  0.501  0.327  0.331  1.0
  O  O16  1  0.017  0.667  0.654  1.0
  O  O17  1  0.999  0.327  0.331  1.0
  O  O18  1  0.483  0.667  0.654  1.0
[/CIF]
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The compound described by Mg3V2(BiO6)2 crystallizes in the monoclinic Pm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(5), and two equivalent O(7) atoms to form MgO5 square pyramids that share  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent V(2)O4 tetrahedra, and corners with two equivalent Mg(3)O5 trigonal bipyramids. In the second Mg site, Mg(2) is bonded to one O(2), two equivalent O(6), and two equivalent O(8) atoms to form MgO5 square pyramids that share  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, and  an edgeedge with one Mg(3)O5 trigonal bipyramid. In the third Mg site, Mg(3) is bonded to one O(3), two equivalent O(6), and two equivalent O(7) atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one V(2)O4 tetrahedra, corners with two equivalent V(1)O4 tetrahedra, and  an edgeedge with one Mg(2)O5 square pyramid. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(4), and two equivalent O(6) atoms to form VO4 tetrahedra that share  a cornercorner with one Mg(1)O5 square pyramid, corners with two equivalent Mg(2)O5 square pyramids, and corners with two equivalent Mg(3)O5 trigonal bipyramids. In the second V site, V(2) is bonded to one O(2), one O(3), and two equivalent O(5) atoms to form VO4 tetrahedra that share  a cornercorner with one Mg(2)O5 square pyramid, corners with two equivalent Mg(1)O5 square pyramids, and  a cornercorner with one Mg(3)O5 trigonal bipyramid. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to two equivalent O(7) and two equivalent O(8) atoms. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to two equivalent O(7) and two equivalent O(8) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one V(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(2) and one V(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mg(3) and one V(2) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one V(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one V(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mg(2), one Mg(3), and one V(1) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Mg(3), one Bi(1), and one Bi(2) atom to form edge-sharing OMg2Bi2 tetrahedra. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Mg(2), one Bi(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_Mg3V2(BiO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.527
_cell_length_b   7.581
_cell_length_c   7.416
_cell_angle_alpha   114.968
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   281.688
_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
  Mg  Mg0  1  0.750  0.100  0.273  1.0
  Mg  Mg1  1  0.250  0.900  0.726  1.0
  Mg  Mg2  1  0.250  0.285  0.107  1.0
  V  V3  1  0.750  0.194  0.800  1.0
  V  V4  1  0.250  0.803  0.201  1.0
  Bi  Bi5  1  0.250  0.410  0.595  1.0
  Bi  Bi6  1  0.750  0.586  0.409  1.0
  O  O7  1  0.750  0.102  0.544  1.0
  O  O8  1  0.250  0.896  0.455  1.0
  O  O9  1  0.250  0.548  0.098  1.0
  O  O10  1  0.750  0.437  0.898  1.0
  O  O11  1  0.003  0.897  0.126  1.0
  O  O12  1  0.485  0.118  0.887  1.0
  O  O13  1  0.015  0.118  0.887  1.0
  O  O14  1  0.497  0.897  0.126  1.0
  O  O15  1  0.501  0.327  0.331  1.0
  O  O16  1  0.017  0.667  0.654  1.0
  O  O17  1  0.999  0.327  0.331  1.0
  O  O18  1  0.483  0.667  0.654  1.0
[/CIF]
.