The crystal structure described by CaAs3 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one As(1), three equivalent As(3), and four equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to one Ca(1), one As(1), one As(2), and one As(3) atom to form distorted AsCaAs3 tetrahedra that share corners with six equivalent As(2)Ca4As2 pentagonal pyramids and corners with five equivalent As(3)Ca3As2 trigonal bipyramids. In the second As site, As(2) is bonded to four equivalent Ca(1), one As(1), and one As(2) atom to form distorted AsCa4As2 pentagonal pyramids that share corners with four equivalent As(2)Ca4As2 pentagonal pyramids, corners with six equivalent As(1)CaAs3 tetrahedra, corners with seven equivalent As(3)Ca3As2 trigonal bipyramids, edges with four equivalent As(2)Ca4As2 pentagonal pyramids, and edges with three equivalent As(3)Ca3As2 trigonal bipyramids. In the third As site, As(3) is bonded to three equivalent Ca(1), one As(1), and one As(3) atom to form distorted AsCa3As2 trigonal bipyramids that share corners with seven equivalent As(2)Ca4As2 pentagonal pyramids, corners with five equivalent As(1)CaAs3 tetrahedra, corners with two equivalent As(3)Ca3As2 trigonal bipyramids, edges with three equivalent As(2)Ca4As2 pentagonal pyramids, and edges with two equivalent As(3)Ca3As2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.891
_cell_length_b   5.889
_cell_length_c   5.962
_cell_angle_alpha   80.310
_cell_angle_beta   70.046
_cell_angle_gamma   75.944
_symmetry_Int_Tables_number   1
_cell_volume   187.791
_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  0.656  0.684  0.630  1.0
  Ca  Ca1  1  0.344  0.316  0.370  1.0
  As  As2  1  0.784  0.008  0.015  1.0
  As  As3  1  0.216  0.992  0.985  1.0
  As  As4  1  0.186  0.858  0.405  1.0
  As  As5  1  0.814  0.142  0.595  1.0
  As  As6  1  0.782  0.590  0.094  1.0
  As  As7  1  0.218  0.410  0.906  1.0
[/CIF]
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The crystal structure described by CaAs3 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one As(1), three equivalent As(3), and four equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to one Ca(1), one As(1), one As(2), and one As(3) atom to form distorted AsCaAs3 tetrahedra that share corners with six equivalent As(2)Ca4As2 pentagonal pyramids and corners with five equivalent As(3)Ca3As2 trigonal bipyramids. In the second As site, As(2) is bonded to four equivalent Ca(1), one As(1), and one As(2) atom to form distorted AsCa4As2 pentagonal pyramids that share corners with four equivalent As(2)Ca4As2 pentagonal pyramids, corners with six equivalent As(1)CaAs3 tetrahedra, corners with seven equivalent As(3)Ca3As2 trigonal bipyramids, edges with four equivalent As(2)Ca4As2 pentagonal pyramids, and edges with three equivalent As(3)Ca3As2 trigonal bipyramids. In the third As site, As(3) is bonded to three equivalent Ca(1), one As(1), and one As(3) atom to form distorted AsCa3As2 trigonal bipyramids that share corners with seven equivalent As(2)Ca4As2 pentagonal pyramids, corners with five equivalent As(1)CaAs3 tetrahedra, corners with two equivalent As(3)Ca3As2 trigonal bipyramids, edges with three equivalent As(2)Ca4As2 pentagonal pyramids, and edges with two equivalent As(3)Ca3As2 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.891
_cell_length_b   5.889
_cell_length_c   5.962
_cell_angle_alpha   80.310
_cell_angle_beta   70.046
_cell_angle_gamma   75.944
_symmetry_Int_Tables_number   1
_cell_volume   187.791
_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  0.656  0.684  0.630  1.0
  Ca  Ca1  1  0.344  0.316  0.370  1.0
  As  As2  1  0.784  0.008  0.015  1.0
  As  As3  1  0.216  0.992  0.985  1.0
  As  As4  1  0.186  0.858  0.405  1.0
  As  As5  1  0.814  0.142  0.595  1.0
  As  As6  1  0.782  0.590  0.094  1.0
  As  As7  1  0.218  0.410  0.906  1.0
[/CIF]
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