The structure described by Mg14CrSiO16 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Cr(1)O6 octahedra; corners with two equivalent Si(1)O6 octahedra; edges with four Mg(2,2)O6 octahedra; edges with four Mg(3,3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Si(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Si(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four Mg(3,3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fifth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four Mg(3,3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the sixth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(4)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. Cr(1) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(3,3)O6 octahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form SiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(2,2)O6 octahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(1) atom to form OMg5Si octahedra that share corners with two equivalent O(2)Mg5Cr octahedra, corners with four equivalent O(1)Mg5Si octahedra, edges with two equivalent O(4)Mg4Si2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(1)Mg5Si octahedra, edges with two equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Cr(1) atom to form OMg5Cr octahedra that share corners with two equivalent O(1)Mg5Si octahedra, corners with four equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(6)Mg4Cr2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(1)Mg5Si octahedra, edges with two equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(6)Mg4Cr2 octahedra,  an edgeedge with one O(4)Mg4Si2 octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(1)Mg5Si octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to four Mg(2,2) and two equivalent Si(1) atoms to form OMg4Si2 octahedra that share corners with two equivalent O(4)Mg4Si2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(1)Mg5Si octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Mg(1); two Mg(2,2); and two Mg(3,3) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with two equivalent O(4)Mg4Si2 octahedra, corners with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(1)Mg5Si octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to four Mg(3,3) and two equivalent Cr(1) atoms to form OMg4Cr2 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Mg14CrSiO16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.648
_cell_length_b   8.648
_cell_length_c   4.264
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   318.893
_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  0.000  0.500  0.000  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.253  0.500  1.0
  Mg  Mg3  1  0.000  0.747  0.500  1.0
  Mg  Mg4  1  0.500  0.246  0.500  1.0
  Mg  Mg5  1  0.500  0.754  0.500  1.0
  Mg  Mg6  1  0.253  0.000  0.500  1.0
  Mg  Mg7  1  0.246  0.500  0.500  1.0
  Mg  Mg8  1  0.747  0.000  0.500  1.0
  Mg  Mg9  1  0.754  0.500  0.500  1.0
  Mg  Mg10  1  0.250  0.250  0.000  1.0
  Mg  Mg11  1  0.250  0.750  0.000  1.0
  Mg  Mg12  1  0.750  0.250  0.000  1.0
  Mg  Mg13  1  0.750  0.750  0.000  1.0
  Cr  Cr14  1  0.500  0.500  0.000  1.0
  Si  Si15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.260  0.000  0.000  1.0
  O  O17  1  0.243  0.500  0.000  1.0
  O  O18  1  0.740  0.000  0.000  1.0
  O  O19  1  0.757  0.500  0.000  1.0
  O  O20  1  0.250  0.250  0.500  1.0
  O  O21  1  0.250  0.750  0.500  1.0
  O  O22  1  0.750  0.250  0.500  1.0
  O  O23  1  0.750  0.750  0.500  1.0
  O  O24  1  0.000  0.000  0.500  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.500  0.000  0.500  1.0
  O  O27  1  0.500  0.500  0.500  1.0
  O  O28  1  0.000  0.260  0.000  1.0
  O  O29  1  0.000  0.740  0.000  1.0
  O  O30  1  0.500  0.243  0.000  1.0
  O  O31  1  0.500  0.757  0.000  1.0
[/CIF]
.
The structure described by Mg14CrSiO16 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. There are six inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Cr(1)O6 octahedra; corners with two equivalent Si(1)O6 octahedra; edges with four Mg(2,2)O6 octahedra; edges with four Mg(3,3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Si(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Si(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four Mg(3,3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fifth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four Mg(3,3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two Mg(3,3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the sixth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(4)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Si(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-5°. Cr(1) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(3,3)O6 octahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form SiO6 octahedra that share corners with two equivalent Si(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(2,2)O6 octahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(1) atom to form OMg5Si octahedra that share corners with two equivalent O(2)Mg5Cr octahedra, corners with four equivalent O(1)Mg5Si octahedra, edges with two equivalent O(4)Mg4Si2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(1)Mg5Si octahedra, edges with two equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Cr(1) atom to form OMg5Cr octahedra that share corners with two equivalent O(1)Mg5Si octahedra, corners with four equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(6)Mg4Cr2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(1)Mg5Si octahedra, edges with two equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third O site, O(3) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(6)Mg4Cr2 octahedra,  an edgeedge with one O(4)Mg4Si2 octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(1)Mg5Si octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to four Mg(2,2) and two equivalent Si(1) atoms to form OMg4Si2 octahedra that share corners with two equivalent O(4)Mg4Si2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(1)Mg5Si octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Mg(1); two Mg(2,2); and two Mg(3,3) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with two equivalent O(4)Mg4Si2 octahedra, corners with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(1)Mg5Si octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to four Mg(3,3) and two equivalent Cr(1) atoms to form OMg4Cr2 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Mg14CrSiO16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.648
_cell_length_b   8.648
_cell_length_c   4.264
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   318.893
_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  0.000  0.500  0.000  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.253  0.500  1.0
  Mg  Mg3  1  0.000  0.747  0.500  1.0
  Mg  Mg4  1  0.500  0.246  0.500  1.0
  Mg  Mg5  1  0.500  0.754  0.500  1.0
  Mg  Mg6  1  0.253  0.000  0.500  1.0
  Mg  Mg7  1  0.246  0.500  0.500  1.0
  Mg  Mg8  1  0.747  0.000  0.500  1.0
  Mg  Mg9  1  0.754  0.500  0.500  1.0
  Mg  Mg10  1  0.250  0.250  0.000  1.0
  Mg  Mg11  1  0.250  0.750  0.000  1.0
  Mg  Mg12  1  0.750  0.250  0.000  1.0
  Mg  Mg13  1  0.750  0.750  0.000  1.0
  Cr  Cr14  1  0.500  0.500  0.000  1.0
  Si  Si15  1  0.000  0.000  0.000  1.0
  O  O16  1  0.260  0.000  0.000  1.0
  O  O17  1  0.243  0.500  0.000  1.0
  O  O18  1  0.740  0.000  0.000  1.0
  O  O19  1  0.757  0.500  0.000  1.0
  O  O20  1  0.250  0.250  0.500  1.0
  O  O21  1  0.250  0.750  0.500  1.0
  O  O22  1  0.750  0.250  0.500  1.0
  O  O23  1  0.750  0.750  0.500  1.0
  O  O24  1  0.000  0.000  0.500  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.500  0.000  0.500  1.0
  O  O27  1  0.500  0.500  0.500  1.0
  O  O28  1  0.000  0.260  0.000  1.0
  O  O29  1  0.000  0.740  0.000  1.0
  O  O30  1  0.500  0.243  0.000  1.0
  O  O31  1  0.500  0.757  0.000  1.0
[/CIF]
.