data_Rb2SrAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.17
_cell_length_b   6.17
_cell_length_c   6.17
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Rb2SrAs
_chemical_formula_sum   'Rb2 Sr1 As1'
_cell_volume   166.37
_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
  Rb  Rb1  1  0.55  0.55  0.55  1.0
  Rb  Rb2  1  0.18  0.18  0.18  1.0
  Sr  Sr3  1  0.37  0.37  0.37  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_Rb2SrAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.17
_cell_length_b   6.17
_cell_length_c   15.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Rb2SrAs
_chemical_formula_sum   'Rb6 Sr3 As3'
_cell_volume   499.11
_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
  Rb  Rb0  3  0.0  0.0  0.45  1.0
  Rb  Rb1  3  0.0  0.0  0.82  1.0
  Sr  Sr2  3  0.0  0.0  0.63  1.0
  As  As3  3  0.0  0.0  0.0  1.0

Rb Rb Sr As
Rb Rb Sr As 0 2 o o o 1 3 o o o 1 2 o o o 
Rb2SrAs crystallizes in the trigonal R3m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 4-coordinate geometry to one Sr(1) and three equivalent As(1) atoms. The Rb(1)-Sr(1) bond length is 2.76 Å. All Rb(1)-As(1) bond lengths are 3.99 Å. In the second Rb site, Rb(2) is bonded in a distorted linear geometry to one Sr(1) and one As(1) atom. The Rb(2)-Sr(1) bond length is 2.76 Å. The Rb(2)-As(1) bond length is 2.76 Å. Sr(1) is bonded to one Rb(1), one Rb(2), and three equivalent As(1) atoms to form corner-sharing SrRb2As3 trigonal bipyramids. All Sr(1)-As(1) bond lengths are 3.60 Å. As(1) is bonded in a 1-coordinate geometry to one Rb(2), three equivalent Rb(1), and three equivalent Sr(1) atoms.