data_Y2MgAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.5
_cell_length_b   6.5
_cell_length_c   6.5
_cell_angle_alpha   134.45
_cell_angle_beta   134.45
_cell_angle_gamma   66.39
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Y2MgAs2
_chemical_formula_sum   'Y2 Mg1 As2'
_cell_volume   137.83
_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
  Y  Y3  1  0.0  0.52  0.72  1.0
  Y  Y4  1  0.52  0.0  0.72  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.0  0.0  0.78  1.0
  As  As1  1  0.0  0.0  0.1  1.0

data_Y2MgAs2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.12
_cell_length_b   7.12
_cell_length_c   6.5
_cell_angle_alpha   90.0
_cell_angle_beta   123.19
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Y2MgAs2
_chemical_formula_sum   'Y4 Mg2 As4'
_cell_volume   275.65
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Y  Y0  4  0.04  0.24  0.8  1.0
  Mg  Mg1  2  0.0  0.0  0.0  1.0
  As  As2  2  0.22  0.0  0.22  1.0
  As  As3  2  0.4  0.5  0.9  1.0

Y Y Mg As As
Y Y Mg As As 0 2 o + + 0 4 o + + 1 2 + o + 1 4 + o + 2 4 o o o 2 3 o o - 
MgY2As2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted linear geometry to two equivalent Y(1), one As(1), and one As(2) atom. Both Mg(1)-Y(1) bond lengths are 2.28 Å. The Mg(1)-As(1) bond length is 1.44 Å. The Mg(1)-As(2) bond length is 0.67 Å. Y(1) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent As(1), and two equivalent As(2) atoms. There is one shorter (2.89 Å) and one longer (3.63 Å) Y(1)-As(1) bond length. There is one shorter (2.26 Å) and one longer (2.92 Å) Y(1)-As(2) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Mg(1) and four equivalent Y(1) atoms. In the second As site, As(2) is bonded in a single-bond geometry to one Mg(1) and four equivalent Y(1) atoms.