data_ScSiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ScSiAs
_chemical_formula_sum   'Sc1 Si1 As1'
_cell_volume   64.9
_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
  Sc  Sc1  1  0.59  0.59  0.59  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.19  0.19  0.19  1.0

data_ScSiAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   11.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   ScSiAs
_chemical_formula_sum   'Sc3 Si3 As3'
_cell_volume   194.7
_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
  Sc  Sc0  3  0.0  0.0  0.41  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  As  As2  3  0.0  0.0  0.81  1.0

Sc Si As
ScSiAs crystallizes in the trigonal R3m space group. Sc(1) is bonded in a distorted hexagonal planar geometry to three equivalent Si(1) and three equivalent As(1) atoms. All Sc(1)-Si(1) bond lengths are 2.72 Å. All Sc(1)-As(1) bond lengths are 2.72 Å. Si(1) is bonded to three equivalent Sc(1) and one As(1) atom to form distorted SiSc3As tetrahedra that share corners with three equivalent As(1)Sc3Si tetrahedra, corners with six equivalent Si(1)Sc3As tetrahedra, and edges with three equivalent As(1)Sc3Si tetrahedra. The Si(1)-As(1) bond length is 2.10 Å. As(1) is bonded to three equivalent Sc(1) and one Si(1) atom to form AsSc3Si tetrahedra that share corners with three equivalent Si(1)Sc3As tetrahedra, corners with six equivalent As(1)Sc3Si tetrahedra, and edges with three equivalent Si(1)Sc3As tetrahedra.