The compound described by MgNd4(RhO3)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(6), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 tetrahedra that share corners with two equivalent Rh(1)O6 octahedra and edges with two equivalent Rh(1)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to one O(6), one O(8), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the third Nd site, Nd(3) is bonded in a 8-coordinate geometry to one O(6), one O(8), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the fourth Nd site, Nd(4) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form RhO6 octahedra that share corners with two equivalent Rh(1)O6 octahedra,  a cornercorner with one Mg(1)O6 tetrahedra, and  an edgeedge with one Mg(1)O6 tetrahedra. The corner-sharing octahedral tilt angles range from 48-49°. In the second Rh site, Rh(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Nd(2), one Nd(3), one Nd(4), one Rh(1), and one Rh(2) atom to form distorted ONd3Rh2 trigonal bipyramids that share corners with three equivalent O(7)Nd2Rh2 tetrahedra,  a cornercorner with one O(1)Nd3Rh2 trigonal bipyramid, corners with two equivalent O(2)Nd3Rh2 trigonal bipyramids,  a cornercorner with one O(5)Nd2Rh2 trigonal pyramid,  an edgeedge with one O(1)Nd3Rh2 trigonal bipyramid, edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids, and  an edgeedge with one O(5)Nd2Rh2 trigonal pyramid. In the second O site, O(2) is bonded to one Nd(1), one Nd(3), one Nd(4), one Rh(1), and one Rh(2) atom to form distorted ONd3Rh2 trigonal bipyramids that share  a cornercorner with one O(2)Nd3Rh2 trigonal bipyramid, corners with two equivalent O(1)Nd3Rh2 trigonal bipyramids,  an edgeedge with one O(7)Nd2Rh2 tetrahedra,  an edgeedge with one O(2)Nd3Rh2 trigonal bipyramid, edges with two equivalent O(1)Nd3Rh2 trigonal bipyramids, and  an edgeedge with one O(5)Nd2Rh2 trigonal pyramid. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nd(4), one Rh(1), and one Rh(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nd(3), one Rh(1), and one Rh(2) atom. In the fifth O site, O(5) is bonded to one Nd(2), one Nd(4), and two equivalent Rh(1) atoms to form distorted ONd2Rh2 trigonal pyramids that share corners with two equivalent O(7)Nd2Rh2 tetrahedra, corners with two equivalent O(1)Nd3Rh2 trigonal bipyramids, edges with two equivalent O(1)Nd3Rh2 trigonal bipyramids, and edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(3), and two equivalent Rh(2) atoms. In the seventh O site, O(7) is bonded to one Nd(2), one Nd(4), and two equivalent Rh(2) atoms to form distorted ONd2Rh2 tetrahedra that share corners with six equivalent O(1)Nd3Rh2 trigonal bipyramids, corners with two equivalent O(5)Nd2Rh2 trigonal pyramids, and edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(3), and two equivalent Rh(1) atoms. is represented by the CIF file [CIF]
data_Nd4Mg(RhO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.508
_cell_length_b   6.442
_cell_length_c   7.547
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   86.815
_symmetry_Int_Tables_number   1
_cell_volume   267.384
_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
  Nd  Nd0  1  0.443  0.586  0.750  1.0
  Nd  Nd1  1  0.982  0.909  0.250  1.0
  Nd  Nd2  1  0.060  0.145  0.750  1.0
  Nd  Nd3  1  0.540  0.401  0.250  1.0
  Mg  Mg4  1  0.924  0.752  0.750  1.0
  Rh  Rh5  1  0.504  0.001  0.500  1.0
  Rh  Rh6  1  0.996  0.488  0.487  1.0
  Rh  Rh7  1  0.996  0.488  0.013  1.0
  Rh  Rh8  1  0.504  0.001  0.000  1.0
  O  O9  1  0.812  0.170  0.447  1.0
  O  O10  1  0.334  0.308  0.550  1.0
  O  O11  1  0.668  0.687  0.044  1.0
  O  O12  1  0.174  0.829  0.935  1.0
  O  O13  1  0.174  0.829  0.565  1.0
  O  O14  1  0.668  0.687  0.456  1.0
  O  O15  1  0.334  0.308  0.950  1.0
  O  O16  1  0.812  0.170  0.053  1.0
  O  O17  1  0.364  0.056  0.250  1.0
  O  O18  1  0.851  0.462  0.750  1.0
  O  O19  1  0.136  0.547  0.250  1.0
  O  O20  1  0.650  0.949  0.750  1.0
[/CIF]
.
The compound described by MgNd4(RhO3)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(6), one O(8), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 tetrahedra that share corners with two equivalent Rh(1)O6 octahedra and edges with two equivalent Rh(1)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to one O(6), one O(8), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. In the third Nd site, Nd(3) is bonded in a 8-coordinate geometry to one O(6), one O(8), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. In the fourth Nd site, Nd(4) is bonded in a 8-coordinate geometry to one O(5), one O(7), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form RhO6 octahedra that share corners with two equivalent Rh(1)O6 octahedra,  a cornercorner with one Mg(1)O6 tetrahedra, and  an edgeedge with one Mg(1)O6 tetrahedra. The corner-sharing octahedral tilt angles range from 48-49°. In the second Rh site, Rh(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Nd(2), one Nd(3), one Nd(4), one Rh(1), and one Rh(2) atom to form distorted ONd3Rh2 trigonal bipyramids that share corners with three equivalent O(7)Nd2Rh2 tetrahedra,  a cornercorner with one O(1)Nd3Rh2 trigonal bipyramid, corners with two equivalent O(2)Nd3Rh2 trigonal bipyramids,  a cornercorner with one O(5)Nd2Rh2 trigonal pyramid,  an edgeedge with one O(1)Nd3Rh2 trigonal bipyramid, edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids, and  an edgeedge with one O(5)Nd2Rh2 trigonal pyramid. In the second O site, O(2) is bonded to one Nd(1), one Nd(3), one Nd(4), one Rh(1), and one Rh(2) atom to form distorted ONd3Rh2 trigonal bipyramids that share  a cornercorner with one O(2)Nd3Rh2 trigonal bipyramid, corners with two equivalent O(1)Nd3Rh2 trigonal bipyramids,  an edgeedge with one O(7)Nd2Rh2 tetrahedra,  an edgeedge with one O(2)Nd3Rh2 trigonal bipyramid, edges with two equivalent O(1)Nd3Rh2 trigonal bipyramids, and  an edgeedge with one O(5)Nd2Rh2 trigonal pyramid. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nd(4), one Rh(1), and one Rh(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nd(3), one Rh(1), and one Rh(2) atom. In the fifth O site, O(5) is bonded to one Nd(2), one Nd(4), and two equivalent Rh(1) atoms to form distorted ONd2Rh2 trigonal pyramids that share corners with two equivalent O(7)Nd2Rh2 tetrahedra, corners with two equivalent O(1)Nd3Rh2 trigonal bipyramids, edges with two equivalent O(1)Nd3Rh2 trigonal bipyramids, and edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(3), and two equivalent Rh(2) atoms. In the seventh O site, O(7) is bonded to one Nd(2), one Nd(4), and two equivalent Rh(2) atoms to form distorted ONd2Rh2 tetrahedra that share corners with six equivalent O(1)Nd3Rh2 trigonal bipyramids, corners with two equivalent O(5)Nd2Rh2 trigonal pyramids, and edges with two equivalent O(2)Nd3Rh2 trigonal bipyramids. In the eighth O site, O(8) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(3), and two equivalent Rh(1) atoms. is represented by the CIF file [CIF]
data_Nd4Mg(RhO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.508
_cell_length_b   6.442
_cell_length_c   7.547
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   86.815
_symmetry_Int_Tables_number   1
_cell_volume   267.384
_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
  Nd  Nd0  1  0.443  0.586  0.750  1.0
  Nd  Nd1  1  0.982  0.909  0.250  1.0
  Nd  Nd2  1  0.060  0.145  0.750  1.0
  Nd  Nd3  1  0.540  0.401  0.250  1.0
  Mg  Mg4  1  0.924  0.752  0.750  1.0
  Rh  Rh5  1  0.504  0.001  0.500  1.0
  Rh  Rh6  1  0.996  0.488  0.487  1.0
  Rh  Rh7  1  0.996  0.488  0.013  1.0
  Rh  Rh8  1  0.504  0.001  0.000  1.0
  O  O9  1  0.812  0.170  0.447  1.0
  O  O10  1  0.334  0.308  0.550  1.0
  O  O11  1  0.668  0.687  0.044  1.0
  O  O12  1  0.174  0.829  0.935  1.0
  O  O13  1  0.174  0.829  0.565  1.0
  O  O14  1  0.668  0.687  0.456  1.0
  O  O15  1  0.334  0.308  0.950  1.0
  O  O16  1  0.812  0.170  0.053  1.0
  O  O17  1  0.364  0.056  0.250  1.0
  O  O18  1  0.851  0.462  0.750  1.0
  O  O19  1  0.136  0.547  0.250  1.0
  O  O20  1  0.650  0.949  0.750  1.0
[/CIF]
.