The material described by Ca7HfN6 crystallizes in the orthorhombic Ibam space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form CaN4 tetrahedra that share corners with two equivalent Hf(1)N4 tetrahedra and  an edgeedge with one Ca(1)N4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. Hf(1) is bonded to four equivalent N(1) atoms to form HfN4 tetrahedra that share corners with four equivalent Ca(1)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(2), and one Hf(1) atom. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1) and four equivalent Ca(2) atoms. is represented by the CIF card [CIF]
data_Ca7HfN6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.388
_cell_length_b   9.345
_cell_length_c   9.345
_cell_angle_alpha   77.999
_cell_angle_beta   70.013
_cell_angle_gamma   70.013
_symmetry_Int_Tables_number   1
_cell_volume   490.110
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.280  0.958  0.042  1.0
  Ca  Ca1  1  0.720  0.042  0.958  1.0
  Ca  Ca2  1  0.220  0.458  0.542  1.0
  Ca  Ca3  1  0.780  0.542  0.458  1.0
  Ca  Ca4  1  0.737  0.151  0.606  1.0
  Ca  Ca5  1  0.506  0.606  0.151  1.0
  Ca  Ca6  1  0.763  0.894  0.349  1.0
  Ca  Ca7  1  0.994  0.349  0.894  1.0
  Ca  Ca8  1  0.263  0.849  0.394  1.0
  Ca  Ca9  1  0.494  0.394  0.849  1.0
  Ca  Ca10  1  0.237  0.106  0.651  1.0
  Ca  Ca11  1  0.006  0.651  0.106  1.0
  Ca  Ca12  1  0.250  0.250  0.250  1.0
  Ca  Ca13  1  0.750  0.750  0.750  1.0
  Hf  Hf14  1  0.750  0.250  0.250  1.0
  Hf  Hf15  1  0.250  0.750  0.750  1.0
  N  N16  1  0.026  0.064  0.279  1.0
  N  N17  1  0.631  0.279  0.064  1.0
  N  N18  1  0.474  0.221  0.436  1.0
  N  N19  1  0.869  0.436  0.221  1.0
  N  N20  1  0.974  0.936  0.721  1.0
  N  N21  1  0.369  0.721  0.936  1.0
  N  N22  1  0.526  0.779  0.564  1.0
  N  N23  1  0.131  0.564  0.779  1.0
  N  N24  1  0.881  0.343  0.657  1.0
  N  N25  1  0.119  0.657  0.343  1.0
  N  N26  1  0.619  0.843  0.157  1.0
  N  N27  1  0.381  0.157  0.843  1.0
[/CIF]
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The material described by Ca7HfN6 crystallizes in the orthorhombic Ibam space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form CaN4 tetrahedra that share corners with two equivalent Hf(1)N4 tetrahedra and  an edgeedge with one Ca(1)N4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. Hf(1) is bonded to four equivalent N(1) atoms to form HfN4 tetrahedra that share corners with four equivalent Ca(1)N4 tetrahedra. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), two equivalent Ca(2), and one Hf(1) atom. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1) and four equivalent Ca(2) atoms. is represented by the CIF card [CIF]
data_Ca7HfN6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.388
_cell_length_b   9.345
_cell_length_c   9.345
_cell_angle_alpha   77.999
_cell_angle_beta   70.013
_cell_angle_gamma   70.013
_symmetry_Int_Tables_number   1
_cell_volume   490.110
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.280  0.958  0.042  1.0
  Ca  Ca1  1  0.720  0.042  0.958  1.0
  Ca  Ca2  1  0.220  0.458  0.542  1.0
  Ca  Ca3  1  0.780  0.542  0.458  1.0
  Ca  Ca4  1  0.737  0.151  0.606  1.0
  Ca  Ca5  1  0.506  0.606  0.151  1.0
  Ca  Ca6  1  0.763  0.894  0.349  1.0
  Ca  Ca7  1  0.994  0.349  0.894  1.0
  Ca  Ca8  1  0.263  0.849  0.394  1.0
  Ca  Ca9  1  0.494  0.394  0.849  1.0
  Ca  Ca10  1  0.237  0.106  0.651  1.0
  Ca  Ca11  1  0.006  0.651  0.106  1.0
  Ca  Ca12  1  0.250  0.250  0.250  1.0
  Ca  Ca13  1  0.750  0.750  0.750  1.0
  Hf  Hf14  1  0.750  0.250  0.250  1.0
  Hf  Hf15  1  0.250  0.750  0.750  1.0
  N  N16  1  0.026  0.064  0.279  1.0
  N  N17  1  0.631  0.279  0.064  1.0
  N  N18  1  0.474  0.221  0.436  1.0
  N  N19  1  0.869  0.436  0.221  1.0
  N  N20  1  0.974  0.936  0.721  1.0
  N  N21  1  0.369  0.721  0.936  1.0
  N  N22  1  0.526  0.779  0.564  1.0
  N  N23  1  0.131  0.564  0.779  1.0
  N  N24  1  0.881  0.343  0.657  1.0
  N  N25  1  0.119  0.657  0.343  1.0
  N  N26  1  0.619  0.843  0.157  1.0
  N  N27  1  0.381  0.157  0.843  1.0
[/CIF]
.