data_Pm2PrAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.4
_cell_length_b   5.4
_cell_length_c   5.4
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Pm2PrAs
_chemical_formula_sum   'Pm2 Pr1 As1'
_cell_volume   111.21
_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
  Pm  Pm1  1  0.73  0.73  0.73  1.0
  Pm  Pm2  1  0.91  0.91  0.91  1.0
  Pr  Pr3  1  0.82  0.82  0.82  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_Pm2PrAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.4
_cell_length_b   5.4
_cell_length_c   13.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Pm2PrAs
_chemical_formula_sum   'Pm6 Pr3 As3'
_cell_volume   333.62
_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
  Pm  Pm0  3  0.0  0.0  0.09  1.0
  Pr  Pr1  3  0.0  0.0  0.18  1.0
  Pm  Pm2  3  0.0  0.0  0.27  1.0
  As  As3  3  0.0  0.0  0.0  1.0

Pm Pm Pr As
Pm2PrAs crystallizes in the trigonal R3m space group. There are two inequivalent Pm sites. In the first Pm site, Pm(1) is bonded to one Pr(1) and three equivalent As(1) atoms to form corner-sharing PmPrAs3 tetrahedra. The Pm(1)-Pr(1) bond length is 1.21 Å. All Pm(1)-As(1) bond lengths are 3.21 Å. In the second Pm site, Pm(2) is bonded in a single-bond geometry to one Pr(1) and one As(1) atom. The Pm(2)-Pr(1) bond length is 1.21 Å. The Pm(2)-As(1) bond length is 1.21 Å. Pr(1) is bonded in a linear geometry to one Pm(1) and one Pm(2) atom. As(1) is bonded in a single-bond geometry to one Pm(2) and three equivalent Pm(1) atoms.