The crystal structure described by Mg3FeAl(SiO4)3 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to one O(4), one O(5), two equivalent O(1), two equivalent O(10), and two equivalent O(9) atoms. Fe(1) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(11), two equivalent O(12), and two equivalent O(2) atoms. Al(1) is bonded to one O(11), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O6 octahedra and corners with five equivalent Si(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-39°. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form SiO6 octahedra that share  a cornercorner with one Al(1)O6 octahedra and corners with five equivalent Si(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-35°. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom to form corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 32-37°. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(2), one O(3), one O(6), and one O(8) atom to form SiO6 octahedra that share  a cornercorner with one Si(2)O6 octahedra and corners with five equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(3), one Si(1), and one Si(2) atom to form distorted OMg2Si2 tetrahedra that share  a cornercorner with one O(7)Mg2AlSi tetrahedra,  a cornercorner with one O(8)Mg2Si2 tetrahedra, and corners with two equivalent O(1)Mg2Si2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Fe(1), one Al(1), and one Si(3) atom to form distorted OAlFe2Si trigonal pyramids that share  a cornercorner with one O(7)Mg2AlSi tetrahedra,  a cornercorner with one O(8)Mg2Si2 tetrahedra, and corners with two equivalent O(2)AlFe2Si trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), one Fe(1), one Al(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Fe(1), one Al(1), and one Si(3) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Mg(2), one Al(1), and one Si(1) atom to form distorted OMg2AlSi tetrahedra that share  a cornercorner with one O(1)Mg2Si2 tetrahedra, corners with two equivalent O(8)Mg2Si2 tetrahedra, and  a cornercorner with one O(2)AlFe2Si trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Mg(2), one Si(2), and one Si(3) atom to form distorted OMg2Si2 tetrahedra that share  a cornercorner with one O(1)Mg2Si2 tetrahedra, corners with two equivalent O(7)Mg2AlSi tetrahedra, and  a cornercorner with one O(2)AlFe2Si trigonal pyramid. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(3), one Si(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(3), one Si(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Fe(1), one Al(1), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Fe(1), one Al(1), and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3AlFe(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.029
_cell_length_b   4.858
_cell_length_c   14.090
_cell_angle_alpha   89.980
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   344.279
_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  0.052  0.241  0.243  1.0
  Mg  Mg1  1  0.054  0.237  0.757  1.0
  Mg  Mg2  1  0.554  0.763  0.243  1.0
  Mg  Mg3  1  0.552  0.759  0.757  1.0
  Mg  Mg4  1  0.436  0.737  0.999  1.0
  Mg  Mg5  1  0.936  0.263  0.001  1.0
  Al  Al6  1  0.506  0.243  0.629  1.0
  Al  Al7  1  0.006  0.757  0.371  1.0
  Fe  Fe8  1  0.441  0.729  0.500  1.0
  Fe  Fe9  1  0.941  0.271  0.500  1.0
  Si  Si10  1  0.493  0.252  0.876  1.0
  Si  Si11  1  0.493  0.251  0.123  1.0
  Si  Si12  1  0.508  0.240  0.371  1.0
  Si  Si13  1  0.993  0.748  0.124  1.0
  Si  Si14  1  0.008  0.760  0.629  1.0
  Si  Si15  1  0.993  0.749  0.877  1.0
  O  O16  1  0.528  0.147  0.999  1.0
  O  O17  1  0.551  0.129  0.497  1.0
  O  O18  1  0.813  0.079  0.347  1.0
  O  O19  1  0.788  0.054  0.150  1.0
  O  O20  1  0.790  0.050  0.850  1.0
  O  O21  1  0.828  0.060  0.652  1.0
  O  O22  1  0.328  0.940  0.348  1.0
  O  O23  1  0.290  0.950  0.150  1.0
  O  O24  1  0.313  0.921  0.653  1.0
  O  O25  1  0.288  0.946  0.850  1.0
  O  O26  1  0.028  0.853  0.001  1.0
  O  O27  1  0.051  0.871  0.503  1.0
  O  O28  1  0.958  0.647  0.244  1.0
  O  O29  1  0.958  0.643  0.751  1.0
  O  O30  1  0.696  0.554  0.903  1.0
  O  O31  1  0.693  0.553  0.096  1.0
  O  O32  1  0.698  0.546  0.406  1.0
  O  O33  1  0.714  0.565  0.593  1.0
  O  O34  1  0.193  0.447  0.904  1.0
  O  O35  1  0.196  0.446  0.097  1.0
  O  O36  1  0.198  0.454  0.594  1.0
  O  O37  1  0.214  0.435  0.407  1.0
  O  O38  1  0.458  0.357  0.249  1.0
  O  O39  1  0.458  0.353  0.756  1.0
[/CIF]
.
The crystal structure described by Mg3FeAl(SiO4)3 crystallizes in the monoclinic P2_1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to one O(12), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to one O(4), one O(5), two equivalent O(1), two equivalent O(10), and two equivalent O(9) atoms. Fe(1) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(11), two equivalent O(12), and two equivalent O(2) atoms. Al(1) is bonded to one O(11), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O6 octahedra and corners with five equivalent Si(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 35-39°. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form SiO6 octahedra that share  a cornercorner with one Al(1)O6 octahedra and corners with five equivalent Si(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-35°. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(4), one O(5), one O(8), and one O(9) atom to form corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 32-37°. In the third Si site, Si(3) is bonded to one O(11), one O(12), one O(2), one O(3), one O(6), and one O(8) atom to form SiO6 octahedra that share  a cornercorner with one Si(2)O6 octahedra and corners with five equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-39°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(3), one Si(1), and one Si(2) atom to form distorted OMg2Si2 tetrahedra that share  a cornercorner with one O(7)Mg2AlSi tetrahedra,  a cornercorner with one O(8)Mg2Si2 tetrahedra, and corners with two equivalent O(1)Mg2Si2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Fe(1), one Al(1), and one Si(3) atom to form distorted OAlFe2Si trigonal pyramids that share  a cornercorner with one O(7)Mg2AlSi tetrahedra,  a cornercorner with one O(8)Mg2Si2 tetrahedra, and corners with two equivalent O(2)AlFe2Si trigonal pyramids. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(2), one Fe(1), one Al(1), and one Si(3) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Mg(3), one Si(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), one Fe(1), one Al(1), and one Si(3) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Mg(2), one Al(1), and one Si(1) atom to form distorted OMg2AlSi tetrahedra that share  a cornercorner with one O(1)Mg2Si2 tetrahedra, corners with two equivalent O(8)Mg2Si2 tetrahedra, and  a cornercorner with one O(2)AlFe2Si trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Mg(2), one Si(2), and one Si(3) atom to form distorted OMg2Si2 tetrahedra that share  a cornercorner with one O(1)Mg2Si2 tetrahedra, corners with two equivalent O(7)Mg2AlSi tetrahedra, and  a cornercorner with one O(2)AlFe2Si trigonal pyramid. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(3), one Si(1), and one Si(2) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(3), one Si(1), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Fe(1), one Al(1), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Fe(1), one Al(1), and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3AlFe(SiO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.029
_cell_length_b   4.858
_cell_length_c   14.090
_cell_angle_alpha   89.980
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   344.279
_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  0.052  0.241  0.243  1.0
  Mg  Mg1  1  0.054  0.237  0.757  1.0
  Mg  Mg2  1  0.554  0.763  0.243  1.0
  Mg  Mg3  1  0.552  0.759  0.757  1.0
  Mg  Mg4  1  0.436  0.737  0.999  1.0
  Mg  Mg5  1  0.936  0.263  0.001  1.0
  Al  Al6  1  0.506  0.243  0.629  1.0
  Al  Al7  1  0.006  0.757  0.371  1.0
  Fe  Fe8  1  0.441  0.729  0.500  1.0
  Fe  Fe9  1  0.941  0.271  0.500  1.0
  Si  Si10  1  0.493  0.252  0.876  1.0
  Si  Si11  1  0.493  0.251  0.123  1.0
  Si  Si12  1  0.508  0.240  0.371  1.0
  Si  Si13  1  0.993  0.748  0.124  1.0
  Si  Si14  1  0.008  0.760  0.629  1.0
  Si  Si15  1  0.993  0.749  0.877  1.0
  O  O16  1  0.528  0.147  0.999  1.0
  O  O17  1  0.551  0.129  0.497  1.0
  O  O18  1  0.813  0.079  0.347  1.0
  O  O19  1  0.788  0.054  0.150  1.0
  O  O20  1  0.790  0.050  0.850  1.0
  O  O21  1  0.828  0.060  0.652  1.0
  O  O22  1  0.328  0.940  0.348  1.0
  O  O23  1  0.290  0.950  0.150  1.0
  O  O24  1  0.313  0.921  0.653  1.0
  O  O25  1  0.288  0.946  0.850  1.0
  O  O26  1  0.028  0.853  0.001  1.0
  O  O27  1  0.051  0.871  0.503  1.0
  O  O28  1  0.958  0.647  0.244  1.0
  O  O29  1  0.958  0.643  0.751  1.0
  O  O30  1  0.696  0.554  0.903  1.0
  O  O31  1  0.693  0.553  0.096  1.0
  O  O32  1  0.698  0.546  0.406  1.0
  O  O33  1  0.714  0.565  0.593  1.0
  O  O34  1  0.193  0.447  0.904  1.0
  O  O35  1  0.196  0.446  0.097  1.0
  O  O36  1  0.198  0.454  0.594  1.0
  O  O37  1  0.214  0.435  0.407  1.0
  O  O38  1  0.458  0.357  0.249  1.0
  O  O39  1  0.458  0.353  0.756  1.0
[/CIF]
.