The crystal structure described by Sc3As2 crystallizes in the tetragonal P4/m space group. There are five inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one As(1) and four equivalent As(2) atoms to form distorted ScAs5 square pyramids that share corners with four equivalent Sc(3)As6 octahedra, corners with four equivalent Sc(1)As5 square pyramids, corners with four equivalent Sc(2)As5 square pyramids,  an edgeedge with one Sc(3)As6 octahedra, edges with two equivalent Sc(2)As5 square pyramids, edges with four equivalent Sc(1)As5 square pyramids, and  a faceface with one Sc(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 25-57°. In the second Sc site, Sc(2) is bonded to one As(2) and four equivalent As(1) atoms to form distorted ScAs5 square pyramids that share corners with two equivalent Sc(3)As6 octahedra, corners with four equivalent Sc(1)As5 square pyramids, corners with four equivalent Sc(2)As5 square pyramids, edges with two equivalent Sc(3)As6 octahedra, edges with two equivalent Sc(1)As5 square pyramids, and edges with four equivalent Sc(2)As5 square pyramids. The corner-sharing octahedral tilt angles are 49°. In the third Sc site, Sc(3) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form ScAs6 octahedra that share corners with four equivalent Sc(2)As5 square pyramids, corners with eight equivalent Sc(1)As5 square pyramids, edges with two equivalent Sc(3)As6 octahedra, edges with two equivalent Sc(1)As5 square pyramids, edges with four equivalent Sc(2)As5 square pyramids, and faces with two equivalent Sc(1)As5 square pyramids. In the fourth Sc site, Sc(4) is bonded in a square co-planar geometry to four equivalent As(1) atoms. In the fifth Sc site, Sc(5) is bonded in a square co-planar geometry to four equivalent As(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Sc(1), one Sc(3), one Sc(4), and four equivalent Sc(2) atoms to form a mixture of distorted corner, edge, and face-sharing AsSc7 pentagonal bipyramids. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Sc(2), one Sc(5), two equivalent Sc(3), and four equivalent Sc(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sc3As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.364
_cell_length_b   10.364
_cell_length_c   3.869
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   415.586
_cell_formula_units_Z   4
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  Sc0  1  0.135  0.807  0.500  1.0
  Sc  Sc1  1  0.865  0.193  0.500  1.0
  Sc  Sc2  1  0.193  0.135  0.500  1.0
  Sc  Sc3  1  0.807  0.865  0.500  1.0
  Sc  Sc4  1  0.395  0.717  0.000  1.0
  Sc  Sc5  1  0.605  0.283  0.000  1.0
  Sc  Sc6  1  0.283  0.395  0.000  1.0
  Sc  Sc7  1  0.717  0.605  0.000  1.0
  Sc  Sc8  1  0.000  0.500  0.500  1.0
  Sc  Sc9  1  0.500  0.000  0.500  1.0
  Sc  Sc10  1  0.500  0.500  0.500  1.0
  Sc  Sc11  1  0.000  0.000  0.000  1.0
  As  As12  1  0.254  0.581  0.500  1.0
  As  As13  1  0.746  0.419  0.500  1.0
  As  As14  1  0.419  0.254  0.500  1.0
  As  As15  1  0.581  0.746  0.500  1.0
  As  As16  1  0.276  0.950  0.000  1.0
  As  As17  1  0.724  0.050  0.000  1.0
  As  As18  1  0.050  0.276  0.000  1.0
  As  As19  1  0.950  0.724  0.000  1.0
[/CIF]
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The crystal structure described by Sc3As2 crystallizes in the tetragonal P4/m space group. There are five inequivalent Sc sites. In the first Sc site, Sc(1) is bonded to one As(1) and four equivalent As(2) atoms to form distorted ScAs5 square pyramids that share corners with four equivalent Sc(3)As6 octahedra, corners with four equivalent Sc(1)As5 square pyramids, corners with four equivalent Sc(2)As5 square pyramids,  an edgeedge with one Sc(3)As6 octahedra, edges with two equivalent Sc(2)As5 square pyramids, edges with four equivalent Sc(1)As5 square pyramids, and  a faceface with one Sc(3)As6 octahedra. The corner-sharing octahedral tilt angles range from 25-57°. In the second Sc site, Sc(2) is bonded to one As(2) and four equivalent As(1) atoms to form distorted ScAs5 square pyramids that share corners with two equivalent Sc(3)As6 octahedra, corners with four equivalent Sc(1)As5 square pyramids, corners with four equivalent Sc(2)As5 square pyramids, edges with two equivalent Sc(3)As6 octahedra, edges with two equivalent Sc(1)As5 square pyramids, and edges with four equivalent Sc(2)As5 square pyramids. The corner-sharing octahedral tilt angles are 49°. In the third Sc site, Sc(3) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form ScAs6 octahedra that share corners with four equivalent Sc(2)As5 square pyramids, corners with eight equivalent Sc(1)As5 square pyramids, edges with two equivalent Sc(3)As6 octahedra, edges with two equivalent Sc(1)As5 square pyramids, edges with four equivalent Sc(2)As5 square pyramids, and faces with two equivalent Sc(1)As5 square pyramids. In the fourth Sc site, Sc(4) is bonded in a square co-planar geometry to four equivalent As(1) atoms. In the fifth Sc site, Sc(5) is bonded in a square co-planar geometry to four equivalent As(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Sc(1), one Sc(3), one Sc(4), and four equivalent Sc(2) atoms to form a mixture of distorted corner, edge, and face-sharing AsSc7 pentagonal bipyramids. In the second As site, As(2) is bonded in a 8-coordinate geometry to one Sc(2), one Sc(5), two equivalent Sc(3), and four equivalent Sc(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sc3As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.364
_cell_length_b   10.364
_cell_length_c   3.869
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   415.586
_cell_formula_units_Z   4
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  Sc0  1  0.135  0.807  0.500  1.0
  Sc  Sc1  1  0.865  0.193  0.500  1.0
  Sc  Sc2  1  0.193  0.135  0.500  1.0
  Sc  Sc3  1  0.807  0.865  0.500  1.0
  Sc  Sc4  1  0.395  0.717  0.000  1.0
  Sc  Sc5  1  0.605  0.283  0.000  1.0
  Sc  Sc6  1  0.283  0.395  0.000  1.0
  Sc  Sc7  1  0.717  0.605  0.000  1.0
  Sc  Sc8  1  0.000  0.500  0.500  1.0
  Sc  Sc9  1  0.500  0.000  0.500  1.0
  Sc  Sc10  1  0.500  0.500  0.500  1.0
  Sc  Sc11  1  0.000  0.000  0.000  1.0
  As  As12  1  0.254  0.581  0.500  1.0
  As  As13  1  0.746  0.419  0.500  1.0
  As  As14  1  0.419  0.254  0.500  1.0
  As  As15  1  0.581  0.746  0.500  1.0
  As  As16  1  0.276  0.950  0.000  1.0
  As  As17  1  0.724  0.050  0.000  1.0
  As  As18  1  0.050  0.276  0.000  1.0
  As  As19  1  0.950  0.724  0.000  1.0
[/CIF]
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