data_MnAs2Pb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.98
_cell_length_b   3.98
_cell_length_c   7.18
_cell_angle_alpha   95.71
_cell_angle_beta   95.71
_cell_angle_gamma   46.45
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnAs2Pb
_chemical_formula_sum   'Mn1 As2 Pb1'
_cell_volume   82.02
_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
  Mn  Mn2  1  0.0  0.0  0.0  1.0
  As  As0  1  0.1  0.0  0.13  1.0
  As  As1  1  0.44  0.0  0.01  1.0
  Pb  Pb3  1  0.27  0.0  0.57  1.0

data_MnAs2Pb
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.14
_cell_length_b   3.98
_cell_length_c   7.18
_cell_angle_alpha   95.71
_cell_angle_beta   90.0
_cell_angle_gamma   113.22
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnAs2Pb
_chemical_formula_sum   'Mn1 As2 Pb1'
_cell_volume   82.02
_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
  Mn  Mn0  1  0.0  0.0  0.0  1.0
  As  As1  1  0.0  0.56  0.99  1.0
  As  As2  1  0.0  0.9  0.87  1.0
  Pb  Pb3  1  0.0  0.73  0.43  1.0

Mn As As Pb
Mn As As Pb 0 1 o o o 0 2 o o o 0 3 o o - 1 2 o o o 1 3 o o o 2 3 o o - 3 3 + - o 
MnPbAs2 crystallizes in the triclinic P1 space group. Mn(1) is bonded in a single-bond geometry to one Pb(1), one As(1), and two equivalent As(2) atoms. The Mn(1)-Pb(1) bond length is 3.38 Å. The Mn(1)-As(1) bond length is 0.97 Å. There is one shorter (1.74 Å) and one longer (2.25 Å) Mn(1)-As(2) bond length. Pb(1) is bonded to one Mn(1), two equivalent Pb(1), one As(1), and one As(2) atom to form corner-sharing PbMnAs2Pb2 trigonal bipyramids. Both Pb(1)-Pb(1) bond lengths are 3.14 Å. The Pb(1)-As(1) bond length is 3.16 Å. The Pb(1)-As(2) bond length is 3.16 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Mn(1) and one Pb(1) atom. In the second As site, As(2) is bonded in a 2-coordinate geometry to two equivalent Mn(1) and one Pb(1) atom.