data_Sr2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.55
_cell_length_b   5.55
_cell_length_c   7.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2As
_chemical_formula_sum   'Sr4 As2'
_cell_volume   189.95
_cell_formula_units_Z   2
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  Sr2  1  0.0  0.0  0.0  1.0
  Sr  Sr3  1  0.0  0.0  0.56  1.0
  Sr  Sr4  1  0.78  0.6  0.78  1.0
  Sr  Sr5  1  0.0  0.2  0.34  1.0
  As  As0  1  0.0  0.2  0.78  1.0
  As  As1  1  0.78  0.6  0.34  1.0

data_Sr2As
_symmetry_space_group_name_H-M   P1
_cell_length_a   5.55
_cell_length_b   5.55
_cell_length_c   7.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2As
_chemical_formula_sum   'Sr4 As2'
_cell_volume   189.95
_cell_formula_units_Z   2
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  Sr0  1  0.0  0.0  0.0  1.0
  Sr  Sr1  1  0.0  0.0  0.56  1.0
  Sr  Sr2  1  0.0  0.2  0.34  1.0
  Sr  Sr3  1  0.78  0.6  0.78  1.0
  As  As4  1  0.0  0.2  0.78  1.0
  As  As5  1  0.78  0.6  0.34  1.0

Sr Sr Sr Sr As As
Sr2As crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted single-bond geometry to one Sr(4), one As(1), and one As(2) atom. The Sr(1)-Sr(4) bond length is 2.67 Å. The Sr(1)-As(1) bond length is 1.94 Å. The Sr(1)-As(2) bond length is 3.08 Å. In the second Sr site, Sr(2) is bonded in a 1-coordinate geometry to one Sr(4), one As(1), and one As(2) atom. The Sr(2)-Sr(4) bond length is 1.94 Å. The Sr(2)-As(1) bond length is 1.94 Å. The Sr(2)-As(2) bond length is 2.48 Å. In the third Sr site, Sr(3) is bonded in a 1-coordinate geometry to one As(1) and one As(2) atom. The Sr(3)-As(1) bond length is 3.03 Å. The Sr(3)-As(2) bond length is 3.14 Å. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one As(1), and three equivalent As(2) atoms. The Sr(4)-As(1) bond length is 3.14 Å. There are a spread of Sr(4)-As(2) bond distances ranging from 2.93-3.73 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Sr(4) atom. In the second As site, As(2) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and three equivalent Sr(4) atoms.