The material structure described by Mg7SiN6 crystallizes in the orthorhombic Ibam space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with two equivalent Si(1)N4 tetrahedra and  an edgeedge with one Mg(1)N4 tetrahedra. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. Si(1) is bonded to four equivalent N(1) atoms to form SiN4 tetrahedra that share corners with four equivalent Mg(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 Mg(1), one Mg(3), two equivalent Mg(2), and one Si(1) atom. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent Mg(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg7SiN6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.496
_cell_length_b   8.195
_cell_length_c   8.195
_cell_angle_alpha   77.772
_cell_angle_beta   70.409
_cell_angle_gamma   70.409
_symmetry_Int_Tables_number   1
_cell_volume   325.563
_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
  Mg  Mg0  1  0.281  0.958  0.042  1.0
  Mg  Mg1  1  0.719  0.042  0.958  1.0
  Mg  Mg2  1  0.219  0.458  0.542  1.0
  Mg  Mg3  1  0.781  0.542  0.458  1.0
  Mg  Mg4  1  0.725  0.151  0.609  1.0
  Mg  Mg5  1  0.515  0.609  0.151  1.0
  Mg  Mg6  1  0.775  0.891  0.349  1.0
  Mg  Mg7  1  0.985  0.349  0.891  1.0
  Mg  Mg8  1  0.275  0.849  0.391  1.0
  Mg  Mg9  1  0.485  0.391  0.849  1.0
  Mg  Mg10  1  0.225  0.109  0.651  1.0
  Mg  Mg11  1  0.015  0.651  0.109  1.0
  Mg  Mg12  1  0.250  0.250  0.250  1.0
  Mg  Mg13  1  0.750  0.750  0.750  1.0
  Si  Si14  1  0.750  0.250  0.250  1.0
  Si  Si15  1  0.250  0.750  0.750  1.0
  N  N16  1  0.022  0.067  0.277  1.0
  N  N17  1  0.634  0.277  0.067  1.0
  N  N18  1  0.478  0.223  0.433  1.0
  N  N19  1  0.866  0.433  0.223  1.0
  N  N20  1  0.978  0.933  0.723  1.0
  N  N21  1  0.366  0.723  0.933  1.0
  N  N22  1  0.522  0.777  0.567  1.0
  N  N23  1  0.134  0.567  0.777  1.0
  N  N24  1  0.871  0.345  0.655  1.0
  N  N25  1  0.129  0.655  0.345  1.0
  N  N26  1  0.629  0.845  0.155  1.0
  N  N27  1  0.371  0.155  0.845  1.0
[/CIF]
.
The material structure described by Mg7SiN6 crystallizes in the orthorhombic Ibam space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with two equivalent Si(1)N4 tetrahedra and  an edgeedge with one Mg(1)N4 tetrahedra. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to four equivalent N(1) atoms. Si(1) is bonded to four equivalent N(1) atoms to form SiN4 tetrahedra that share corners with four equivalent Mg(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 Mg(1), one Mg(3), two equivalent Mg(2), and one Si(1) atom. In the second N site, N(2) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent Mg(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg7SiN6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.496
_cell_length_b   8.195
_cell_length_c   8.195
_cell_angle_alpha   77.772
_cell_angle_beta   70.409
_cell_angle_gamma   70.409
_symmetry_Int_Tables_number   1
_cell_volume   325.563
_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
  Mg  Mg0  1  0.281  0.958  0.042  1.0
  Mg  Mg1  1  0.719  0.042  0.958  1.0
  Mg  Mg2  1  0.219  0.458  0.542  1.0
  Mg  Mg3  1  0.781  0.542  0.458  1.0
  Mg  Mg4  1  0.725  0.151  0.609  1.0
  Mg  Mg5  1  0.515  0.609  0.151  1.0
  Mg  Mg6  1  0.775  0.891  0.349  1.0
  Mg  Mg7  1  0.985  0.349  0.891  1.0
  Mg  Mg8  1  0.275  0.849  0.391  1.0
  Mg  Mg9  1  0.485  0.391  0.849  1.0
  Mg  Mg10  1  0.225  0.109  0.651  1.0
  Mg  Mg11  1  0.015  0.651  0.109  1.0
  Mg  Mg12  1  0.250  0.250  0.250  1.0
  Mg  Mg13  1  0.750  0.750  0.750  1.0
  Si  Si14  1  0.750  0.250  0.250  1.0
  Si  Si15  1  0.250  0.750  0.750  1.0
  N  N16  1  0.022  0.067  0.277  1.0
  N  N17  1  0.634  0.277  0.067  1.0
  N  N18  1  0.478  0.223  0.433  1.0
  N  N19  1  0.866  0.433  0.223  1.0
  N  N20  1  0.978  0.933  0.723  1.0
  N  N21  1  0.366  0.723  0.933  1.0
  N  N22  1  0.522  0.777  0.567  1.0
  N  N23  1  0.134  0.567  0.777  1.0
  N  N24  1  0.871  0.345  0.655  1.0
  N  N25  1  0.129  0.655  0.345  1.0
  N  N26  1  0.629  0.845  0.155  1.0
  N  N27  1  0.371  0.155  0.845  1.0
[/CIF]
.