data_MgScAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.5
_cell_length_b   4.5
_cell_length_c   4.5
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgScAs
_chemical_formula_sum   'Mg1 Sc1 As1'
_cell_volume   64.29
_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
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Sc  Sc2  1  0.18  0.18  0.18  1.0
  As  As0  1  0.59  0.59  0.59  1.0

data_MgScAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.5
_cell_length_b   4.5
_cell_length_c   11.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgScAs
_chemical_formula_sum   'Mg3 Sc3 As3'
_cell_volume   192.86
_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
  Mg  Mg0  3  0.0  0.0  0.0  1.0
  Sc  Sc1  3  0.0  0.0  0.82  1.0
  As  As2  3  0.0  0.0  0.41  1.0

Mg Sc As
Mg Sc As 0 1 o o o 0 2 o - - 0 2 - o - 0 2 - - o 1 2 o o - 1 2 o - o 1 2 - o o 
MgScAs crystallizes in the trigonal R3m space group. Mg(1) is bonded to one Sc(1) and three equivalent As(1) atoms to form MgScAs3 tetrahedra that share corners with three equivalent Sc(1)MgAs3 tetrahedra, corners with six equivalent Mg(1)ScAs3 tetrahedra, and edges with three equivalent Sc(1)MgAs3 tetrahedra. The Mg(1)-Sc(1) bond length is 1.98 Å. All Mg(1)-As(1) bond lengths are 2.73 Å. Sc(1) is bonded to one Mg(1) and three equivalent As(1) atoms to form ScMgAs3 tetrahedra that share corners with three equivalent Mg(1)ScAs3 tetrahedra, corners with six equivalent Sc(1)MgAs3 tetrahedra, and edges with three equivalent Mg(1)ScAs3 tetrahedra. All Sc(1)-As(1) bond lengths are 2.73 Å. As(1) is bonded in a distorted hexagonal planar geometry to three equivalent Mg(1) and three equivalent Sc(1) atoms.