data_SrCaMgRh
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   5.2
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrCaMgRh
_chemical_formula_sum   'Sr1 Ca1 Mg1 Rh1'
_cell_volume   99.58
_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
  Sr  Sr3  1  0.84  0.84  0.84  1.0
  Ca  Ca0  1  0.68  0.68  0.68  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Rh  Rh2  1  0.52  0.52  0.52  1.0

data_SrCaMgRh
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   12.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrCaMgRh
_chemical_formula_sum   'Sr3 Ca3 Mg3 Rh3'
_cell_volume   298.74
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Sr  Sr0  3  0.0  0.0  0.16  1.0
  Ca  Ca1  3  0.0  0.0  0.32  1.0
  Mg  Mg2  3  0.0  0.0  0.0  1.0
  Rh  Rh3  3  0.0  0.0  0.48  1.0

Sr Ca Mg Rh
SrCaMgRh crystallizes in the trigonal R3m space group. Sr(1) is bonded to one Ca(1), one Mg(1), and three equivalent Rh(1) atoms to form SrCaMgRh3 trigonal bipyramids that share corners with six equivalent Sr(1)CaMgRh3 trigonal bipyramids and  a cornercorner with one Rh(1)Sr3Ca trigonal pyramid. The Sr(1)-Ca(1) bond length is 2.05 Å. The Sr(1)-Mg(1) bond length is 2.05 Å. All Sr(1)-Rh(1) bond lengths are 3.01 Å. Ca(1) is bonded in a 1-coordinate geometry to one Sr(1) and one Rh(1) atom. The Ca(1)-Rh(1) bond length is 2.05 Å. Mg(1) is bonded in a distorted single-bond geometry to one Sr(1) atom. Rh(1) is bonded to three equivalent Sr(1) and one Ca(1) atom to form distorted RhSr3Ca trigonal pyramids that share  a cornercorner with one Sr(1)CaMgRh3 trigonal bipyramid and corners with six equivalent Rh(1)Sr3Ca trigonal pyramids.