data_MgSc3Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgSc3Cu
_chemical_formula_sum   'Mg1 Sc3 Cu1'
_cell_volume   138.84
_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
  Mg  Mg3  1  0.0  0.0  0.0  1.0
  Sc  Sc0  1  0.0  0.59  0.0  1.0
  Sc  Sc1  1  0.0  0.0  0.59  1.0
  Sc  Sc2  1  0.59  0.0  0.0  1.0
  Cu  Cu4  1  0.59  0.59  0.59  1.0

data_MgSc3Cu
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.32
_cell_length_b   7.32
_cell_length_c   8.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgSc3Cu
_chemical_formula_sum   'Mg3 Sc9 Cu3'
_cell_volume   416.52
_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  9  0.06  0.53  0.53  1.0
  Cu  Cu2  3  0.0  0.0  0.59  1.0

Mg Sc Sc Sc Cu
Mg Sc Sc Sc Cu 0 3 - o o 0 1 o - o 0 2 o o - 0 4 - - - 1 4 o o - 1 4 - o o 1 4 - o - 2 4 o - o 2 4 - o o 2 4 - - o 3 4 o o - 3 4 o - o 3 4 o - - 
MgSc3Cu is Pb (Zr_0.50 Ti_0.48) O_3 structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded to six equivalent Sc(1) atoms to form distorted corner-sharing MgSc6 octahedra. The corner-sharing octahedra are not tilted. There are three shorter (2.13 Å) and three longer (3.05 Å) Mg(1)-Sc(1) bond lengths. Sc(1) is bonded in a 3-coordinate geometry to two equivalent Mg(1) and one Cu(1) atom. The Sc(1)-Cu(1) bond length is 3.01 Å. Cu(1) is bonded in a 3-coordinate geometry to three equivalent Sc(1) atoms.