data_Ca2ZrAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   5.17
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2ZrAs
_chemical_formula_sum   'Ca2 Zr1 As1'
_cell_volume   97.84
_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
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Ca  Ca2  1  0.49  0.49  0.49  1.0
  Zr  Zr3  1  0.83  0.83  0.83  1.0
  As  As0  1  0.66  0.66  0.66  1.0

data_Ca2ZrAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   12.67
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ca2ZrAs
_chemical_formula_sum   'Ca6 Zr3 As3'
_cell_volume   293.51
_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
  Ca  Ca0  3  0.0  0.0  0.0  1.0
  Ca  Ca1  3  0.0  0.0  0.51  1.0
  Zr  Zr2  3  0.0  0.0  0.17  1.0
  As  As3  3  0.0  0.0  0.34  1.0

Ca Ca Zr As
Ca2ZrAs crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one Zr(1) and three equivalent As(1) atoms to form CaZrAs3 trigonal pyramids that share  a cornercorner with one As(1)Ca4Zr trigonal bipyramid and corners with six equivalent Ca(1)ZrAs3 trigonal pyramids. The Ca(1)-Zr(1) bond length is 2.17 Å. All Ca(1)-As(1) bond lengths are 2.99 Å. In the second Ca site, Ca(2) is bonded in a distorted single-bond geometry to one As(1) atom. The Ca(2)-As(1) bond length is 2.17 Å. Zr(1) is bonded in a 2-coordinate geometry to one Ca(1) and one As(1) atom. The Zr(1)-As(1) bond length is 2.17 Å. As(1) is bonded to one Ca(2), three equivalent Ca(1), and one Zr(1) atom to form distorted AsCa4Zr trigonal bipyramids that share corners with six equivalent As(1)Ca4Zr trigonal bipyramids and  a cornercorner with one Ca(1)ZrAs3 trigonal pyramid.