data_MgZrSn2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.16
_cell_length_b   5.16
_cell_length_c   5.16
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgZrSn2
_chemical_formula_sum   'Mg1 Zr1 Sn2'
_cell_volume   97.38
_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  Mg0  1  0.0  0.0  0.0  1.0
  Zr  Zr3  1  0.83  0.83  0.83  1.0
  Sn  Sn1  1  0.65  0.65  0.65  1.0
  Sn  Sn2  1  0.48  0.48  0.48  1.0

data_MgZrSn2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.16
_cell_length_b   5.16
_cell_length_c   12.65
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgZrSn2
_chemical_formula_sum   'Mg3 Zr3 Sn6'
_cell_volume   292.15
_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
  Zr  Zr1  3  0.0  0.0  0.17  1.0
  Sn  Sn2  3  0.0  0.0  0.35  1.0
  Sn  Sn3  3  0.0  0.0  0.52  1.0

Mg Zr Sn Sn
Mg Zr Sn Sn 0 1 - - - 1 2 o o o 2 3 o o o 
MgZrSn2 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one Zr(1) and three equivalent Sn(1) atoms to form distorted MgZrSn3 trigonal pyramids that share corners with three equivalent Zr(1)MgSn4 trigonal bipyramids, corners with six equivalent Mg(1)ZrSn3 trigonal pyramids, and edges with three equivalent Sn(2)Zr3Sn trigonal pyramids. The Mg(1)-Zr(1) bond length is 2.20 Å. All Mg(1)-Sn(1) bond lengths are 2.99 Å. Zr(1) is bonded to one Mg(1), one Sn(1), and three equivalent Sn(2) atoms to form distorted ZrMgSn4 trigonal bipyramids that share corners with six equivalent Zr(1)MgSn4 trigonal bipyramids,  a cornercorner with one Sn(2)Zr3Sn trigonal pyramid, and corners with three equivalent Mg(1)ZrSn3 trigonal pyramids. The Zr(1)-Sn(1) bond length is 2.20 Å. All Zr(1)-Sn(2) bond lengths are 2.99 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted single-bond geometry to three equivalent Mg(1), one Zr(1), and one Sn(2) atom. The Sn(1)-Sn(2) bond length is 2.20 Å. In the second Sn site, Sn(2) is bonded to three equivalent Zr(1) and one Sn(1) atom to form distorted SnZr3Sn trigonal pyramids that share  a cornercorner with one Zr(1)MgSn4 trigonal bipyramid, corners with six equivalent Sn(2)Zr3Sn trigonal pyramids, and edges with three equivalent Mg(1)ZrSn3 trigonal pyramids.