data_Sc2AsO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.37
_cell_length_b   6.37
_cell_length_c   6.37
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sc2AsO4
_chemical_formula_sum   'Sc4 As2 O8'
_cell_volume   182.98
_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
  Sc  Sc10  1  0.38  0.38  0.63  1.0
  Sc  Sc11  1  0.63  0.63  0.63  1.0
  Sc  Sc12  1  0.63  0.38  0.38  1.0
  Sc  Sc13  1  0.38  0.63  0.38  1.0
  As  As0  1  0.0  0.0  0.0  1.0
  As  As1  1  0.25  0.25  0.25  1.0
  O  O2  1  0.52  0.52  0.52  1.0
  O  O3  1  0.52  0.5  0.5  1.0
  O  O4  1  0.5  0.52  0.5  1.0
  O  O5  1  0.77  0.77  0.75  1.0
  O  O6  1  0.5  0.5  0.52  1.0
  O  O7  1  0.77  0.75  0.77  1.0
  O  O8  1  0.75  0.75  0.75  1.0
  O  O9  1  0.75  0.77  0.77  1.0

data_Sc2AsO4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.37
_cell_length_b   6.37
_cell_length_c   15.61
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Sc2AsO4
_chemical_formula_sum   'Sc12 As6 O24'
_cell_volume   548.95
_cell_formula_units_Z   6
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  9  0.08  0.17  0.54  1.0
  Sc  Sc1  3  0.0  0.0  0.37  1.0
  As  As2  3  0.0  0.0  0.0  1.0
  As  As3  3  0.0  0.0  0.75  1.0
  O  O4  9  0.01  0.01  0.5  1.0
  O  O5  9  0.01  0.01  0.24  1.0
  O  O6  3  0.0  0.0  0.25  1.0
  O  O7  3  0.0  0.0  0.48  1.0

Sc Sc Sc Sc As As O O O O O O O O
Sc2AsO4 crystallizes in the trigonal R3m space group. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a single-bond geometry to one As(1), two equivalent As(2), and one O(2) atom. The Sc(1)-As(1) bond length is 3.42 Å. There is one shorter (3.35 Å) and one longer (3.42 Å) Sc(1)-As(2) bond length. The Sc(1)-O(2) bond length is 1.05 Å. In the second Sc site, Sc(2) is bonded in a linear geometry to one O(1) and one O(4) atom. The Sc(2)-O(1) bond length is 1.82 Å. The Sc(2)-O(4) bond length is 1.82 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 3-coordinate geometry to three equivalent Sc(1) atoms. In the second As site, As(2) is bonded in a 6-coordinate geometry to six equivalent Sc(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sc(2) and three equivalent O(2) atoms. All O(1)-O(2) bond lengths are 0.22 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sc(1), one O(1), and two equivalent O(2) atoms. Both O(2)-O(2) bond lengths are 0.13 Å. In the third O site, O(3) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(3) atoms. The O(3)-O(4) bond length is 0.22 Å. Both O(3)-O(3) bond lengths are 0.13 Å. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Sc(2) and three equivalent O(3) atoms.