The compound described by BiMg2PO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with two equivalent Mg(2)O5 trigonal bipyramids, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. In the second Mg site, Mg(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form MgO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. Bi(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. P(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Mg(1)O5 trigonal bipyramids and corners with three equivalent Mg(2)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), and two equivalent Bi(1) atoms to form a mixture of corner and edge-sharing OMg2Bi2 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(2), and one P(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Mg(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Mg2BiPO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.283
_cell_length_b   7.806
_cell_length_c   11.857
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   488.993
_cell_formula_units_Z   4
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  0.811  0.600  1.0
  Mg  Mg1  1  0.750  0.296  0.093  1.0
  Mg  Mg2  1  0.750  0.204  0.593  1.0
  Mg  Mg3  1  0.250  0.311  0.900  1.0
  Mg  Mg4  1  0.250  0.796  0.407  1.0
  Mg  Mg5  1  0.250  0.704  0.907  1.0
  Mg  Mg6  1  0.250  0.189  0.400  1.0
  Mg  Mg7  1  0.750  0.689  0.100  1.0
  Bi  Bi8  1  0.250  0.489  0.598  1.0
  Bi  Bi9  1  0.250  0.011  0.098  1.0
  Bi  Bi10  1  0.750  0.511  0.402  1.0
  Bi  Bi11  1  0.750  0.989  0.902  1.0
  P  P12  1  0.750  0.522  0.802  1.0
  P  P13  1  0.250  0.022  0.698  1.0
  P  P14  1  0.250  0.478  0.198  1.0
  P  P15  1  0.750  0.978  0.302  1.0
  O  O16  1  0.498  0.327  0.494  1.0
  O  O17  1  0.502  0.673  0.506  1.0
  O  O18  1  0.002  0.327  0.494  1.0
  O  O19  1  0.008  0.007  0.625  1.0
  O  O20  1  0.992  0.507  0.875  1.0
  O  O21  1  0.250  0.881  0.787  1.0
  O  O22  1  0.750  0.800  0.248  1.0
  O  O23  1  0.750  0.119  0.213  1.0
  O  O24  1  0.250  0.300  0.252  1.0
  O  O25  1  0.250  0.619  0.287  1.0
  O  O26  1  0.492  0.493  0.125  1.0
  O  O27  1  0.998  0.827  0.006  1.0
  O  O28  1  0.998  0.673  0.506  1.0
  O  O29  1  0.008  0.493  0.125  1.0
  O  O30  1  0.002  0.173  0.994  1.0
  O  O31  1  0.508  0.993  0.375  1.0
  O  O32  1  0.250  0.200  0.752  1.0
  O  O33  1  0.750  0.700  0.748  1.0
  O  O34  1  0.498  0.173  0.994  1.0
  O  O35  1  0.492  0.007  0.625  1.0
  O  O36  1  0.992  0.993  0.375  1.0
  O  O37  1  0.750  0.381  0.713  1.0
  O  O38  1  0.508  0.507  0.875  1.0
  O  O39  1  0.502  0.827  0.006  1.0
[/CIF]
.
The compound described by BiMg2PO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with two equivalent Mg(2)O5 trigonal bipyramids, and  an edgeedge with one Mg(2)O5 trigonal bipyramid. In the second Mg site, Mg(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form MgO5 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. Bi(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. P(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Mg(1)O5 trigonal bipyramids and corners with three equivalent Mg(2)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), and two equivalent Bi(1) atoms to form a mixture of corner and edge-sharing OMg2Bi2 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Mg(2), and one P(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Mg(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(1) atom. is represented by the CIF file [CIF]
data_Mg2BiPO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.283
_cell_length_b   7.806
_cell_length_c   11.857
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   488.993
_cell_formula_units_Z   4
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  0.811  0.600  1.0
  Mg  Mg1  1  0.750  0.296  0.093  1.0
  Mg  Mg2  1  0.750  0.204  0.593  1.0
  Mg  Mg3  1  0.250  0.311  0.900  1.0
  Mg  Mg4  1  0.250  0.796  0.407  1.0
  Mg  Mg5  1  0.250  0.704  0.907  1.0
  Mg  Mg6  1  0.250  0.189  0.400  1.0
  Mg  Mg7  1  0.750  0.689  0.100  1.0
  Bi  Bi8  1  0.250  0.489  0.598  1.0
  Bi  Bi9  1  0.250  0.011  0.098  1.0
  Bi  Bi10  1  0.750  0.511  0.402  1.0
  Bi  Bi11  1  0.750  0.989  0.902  1.0
  P  P12  1  0.750  0.522  0.802  1.0
  P  P13  1  0.250  0.022  0.698  1.0
  P  P14  1  0.250  0.478  0.198  1.0
  P  P15  1  0.750  0.978  0.302  1.0
  O  O16  1  0.498  0.327  0.494  1.0
  O  O17  1  0.502  0.673  0.506  1.0
  O  O18  1  0.002  0.327  0.494  1.0
  O  O19  1  0.008  0.007  0.625  1.0
  O  O20  1  0.992  0.507  0.875  1.0
  O  O21  1  0.250  0.881  0.787  1.0
  O  O22  1  0.750  0.800  0.248  1.0
  O  O23  1  0.750  0.119  0.213  1.0
  O  O24  1  0.250  0.300  0.252  1.0
  O  O25  1  0.250  0.619  0.287  1.0
  O  O26  1  0.492  0.493  0.125  1.0
  O  O27  1  0.998  0.827  0.006  1.0
  O  O28  1  0.998  0.673  0.506  1.0
  O  O29  1  0.008  0.493  0.125  1.0
  O  O30  1  0.002  0.173  0.994  1.0
  O  O31  1  0.508  0.993  0.375  1.0
  O  O32  1  0.250  0.200  0.752  1.0
  O  O33  1  0.750  0.700  0.748  1.0
  O  O34  1  0.498  0.173  0.994  1.0
  O  O35  1  0.492  0.007  0.625  1.0
  O  O36  1  0.992  0.993  0.375  1.0
  O  O37  1  0.750  0.381  0.713  1.0
  O  O38  1  0.508  0.507  0.875  1.0
  O  O39  1  0.502  0.827  0.006  1.0
[/CIF]
.