The material described by Ca2As crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted square co-planar geometry to four equivalent As(1) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to five equivalent As(1) atoms. As(1) is bonded in a 9-coordinate geometry to four equivalent Ca(1) and five equivalent Ca(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.562
_cell_length_b   4.562
_cell_length_c   8.537
_cell_angle_alpha   105.504
_cell_angle_beta   105.504
_cell_angle_gamma   90.013
_symmetry_Int_Tables_number   1
_cell_volume   164.514
_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
  Ca  Ca0  1  0.500  0.000  0.000  1.0
  Ca  Ca1  1  0.000  0.500  0.000  1.0
  Ca  Ca2  1  0.321  0.321  0.642  1.0
  Ca  Ca3  1  0.679  0.679  0.358  1.0
  As  As4  1  0.134  0.134  0.269  1.0
  As  As5  1  0.866  0.866  0.731  1.0
[/CIF]
.
The material described by Ca2As crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted square co-planar geometry to four equivalent As(1) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to five equivalent As(1) atoms. As(1) is bonded in a 9-coordinate geometry to four equivalent Ca(1) and five equivalent Ca(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.562
_cell_length_b   4.562
_cell_length_c   8.537
_cell_angle_alpha   105.504
_cell_angle_beta   105.504
_cell_angle_gamma   90.013
_symmetry_Int_Tables_number   1
_cell_volume   164.514
_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
  Ca  Ca0  1  0.500  0.000  0.000  1.0
  Ca  Ca1  1  0.000  0.500  0.000  1.0
  Ca  Ca2  1  0.321  0.321  0.642  1.0
  Ca  Ca3  1  0.679  0.679  0.358  1.0
  As  As4  1  0.134  0.134  0.269  1.0
  As  As5  1  0.866  0.866  0.731  1.0
[/CIF]
.