data_Mg2ZrP2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.41
_cell_length_b   5.41
_cell_length_c   5.41
_cell_angle_alpha   127.47
_cell_angle_beta   127.47
_cell_angle_gamma   77.49
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2ZrP2
_chemical_formula_sum   'Mg2 Zr1 P2'
_cell_volume   96.59
_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  0.54  1.0
  Mg  Mg1  1  0.0  0.0  0.89  1.0
  Zr  Zr4  1  0.0  0.0  0.0  1.0
  P  P2  1  0.0  0.39  0.11  1.0
  P  P3  1  0.39  0.0  0.11  1.0

data_Mg2ZrP2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.77
_cell_length_b   6.77
_cell_length_c   5.41
_cell_angle_alpha   90.0
_cell_angle_beta   128.75
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2ZrP2
_chemical_formula_sum   'Mg4 Zr2 P4'
_cell_volume   193.18
_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
  Mg  Mg0  2  0.0  0.0  0.54  1.0
  Mg  Mg1  2  0.0  0.0  0.89  1.0
  Zr  Zr2  2  0.0  0.0  0.0  1.0
  P  P3  4  0.3  0.3  0.72  1.0

Mg Mg Zr P P
Mg2ZrP2 crystallizes in the monoclinic Cm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to one Mg(2), one Zr(1), and four equivalent P(1) atoms. The Mg(1)-Mg(2) bond length is 1.91 Å. The Mg(1)-Zr(1) bond length is 2.92 Å. There are two shorter (2.45 Å) and two longer (2.63 Å) Mg(1)-P(1) bond lengths. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Mg(1), one Zr(1), and two equivalent P(1) atoms. The Mg(2)-Zr(1) bond length is 0.57 Å. Both Mg(2)-P(1) bond lengths are 1.69 Å. Zr(1) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(2), and two equivalent P(1) atoms. Both Zr(1)-P(1) bond lengths are 1.83 Å. P(1) is bonded in a 4-coordinate geometry to one Mg(2), two equivalent Mg(1), and one Zr(1) atom.