The compound described by Be3Fe4Si3SO12 crystallizes in the trigonal R3c space group. Be(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form BeO4 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one S(1), one O(1), one O(2), and one O(4) atom to form distorted FeSO3 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with two equivalent Fe(1)SO3 tetrahedra, corners with three equivalent Be(1)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one S(1) and three equivalent O(3) atoms to form FeSO3 tetrahedra that share corners with three equivalent Be(1)O4 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with four equivalent Be(1)O4 tetrahedra. S(1) is bonded in a tetrahedral geometry to one Fe(2) and three equivalent Fe(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Be(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Be3Fe4Si3SO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.306
_cell_length_b   8.306
_cell_length_c   8.306
_cell_angle_alpha   89.559
_cell_angle_beta   89.559
_cell_angle_gamma   89.560
_symmetry_Int_Tables_number   1
_cell_volume   573.015
_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
  Be  Be0  1  0.751  0.500  0.002  1.0
  Be  Be1  1  0.500  0.002  0.751  1.0
  Be  Be2  1  0.502  0.000  0.251  1.0
  Be  Be3  1  0.000  0.251  0.502  1.0
  Be  Be4  1  0.002  0.751  0.500  1.0
  Be  Be5  1  0.251  0.502  0.000  1.0
  Fe  Fe6  1  0.670  0.667  0.330  1.0
  Fe  Fe7  1  0.331  0.331  0.331  1.0
  Fe  Fe8  1  0.170  0.830  0.167  1.0
  Fe  Fe9  1  0.831  0.831  0.831  1.0
  Fe  Fe10  1  0.167  0.170  0.830  1.0
  Fe  Fe11  1  0.330  0.670  0.667  1.0
  Fe  Fe12  1  0.830  0.167  0.170  1.0
  Fe  Fe13  1  0.667  0.330  0.670  1.0
  Si  Si14  1  0.253  0.997  0.503  1.0
  Si  Si15  1  0.497  0.753  0.003  1.0
  Si  Si16  1  0.503  0.253  0.997  1.0
  Si  Si17  1  0.753  0.003  0.497  1.0
  Si  Si18  1  0.997  0.503  0.253  1.0
  Si  Si19  1  0.003  0.497  0.753  1.0
  S  S20  1  0.000  0.000  0.000  1.0
  S  S21  1  0.500  0.500  0.500  1.0
  O  O22  1  0.145  0.415  0.862  1.0
  O  O23  1  0.140  0.588  0.141  1.0
  O  O24  1  0.589  0.864  0.865  1.0
  O  O25  1  0.415  0.862  0.145  1.0
  O  O26  1  0.147  0.856  0.416  1.0
  O  O27  1  0.862  0.145  0.415  1.0
  O  O28  1  0.645  0.362  0.915  1.0
  O  O29  1  0.856  0.416  0.147  1.0
  O  O30  1  0.865  0.589  0.864  1.0
  O  O31  1  0.416  0.147  0.856  1.0
  O  O32  1  0.588  0.141  0.140  1.0
  O  O33  1  0.141  0.140  0.588  1.0
  O  O34  1  0.864  0.865  0.589  1.0
  O  O35  1  0.089  0.365  0.364  1.0
  O  O36  1  0.647  0.916  0.356  1.0
  O  O37  1  0.364  0.089  0.365  1.0
  O  O38  1  0.088  0.640  0.641  1.0
  O  O39  1  0.362  0.915  0.645  1.0
  O  O40  1  0.915  0.645  0.362  1.0
  O  O41  1  0.916  0.356  0.647  1.0
  O  O42  1  0.641  0.088  0.640  1.0
  O  O43  1  0.640  0.641  0.088  1.0
  O  O44  1  0.365  0.364  0.089  1.0
  O  O45  1  0.356  0.647  0.916  1.0
[/CIF]
.
The compound described by Be3Fe4Si3SO12 crystallizes in the trigonal R3c space group. Be(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form BeO4 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one S(1), one O(1), one O(2), and one O(4) atom to form distorted FeSO3 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with two equivalent Fe(1)SO3 tetrahedra, corners with three equivalent Be(1)O4 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one S(1) and three equivalent O(3) atoms to form FeSO3 tetrahedra that share corners with three equivalent Be(1)O4 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with three equivalent Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Fe(2)SO3 tetrahedra, corners with three equivalent Fe(1)SO3 tetrahedra, and corners with four equivalent Be(1)O4 tetrahedra. S(1) is bonded in a tetrahedral geometry to one Fe(2) and three equivalent Fe(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Be(1), one Fe(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Be(1), one Fe(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Be3Fe4Si3SO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.306
_cell_length_b   8.306
_cell_length_c   8.306
_cell_angle_alpha   89.559
_cell_angle_beta   89.559
_cell_angle_gamma   89.560
_symmetry_Int_Tables_number   1
_cell_volume   573.015
_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
  Be  Be0  1  0.751  0.500  0.002  1.0
  Be  Be1  1  0.500  0.002  0.751  1.0
  Be  Be2  1  0.502  0.000  0.251  1.0
  Be  Be3  1  0.000  0.251  0.502  1.0
  Be  Be4  1  0.002  0.751  0.500  1.0
  Be  Be5  1  0.251  0.502  0.000  1.0
  Fe  Fe6  1  0.670  0.667  0.330  1.0
  Fe  Fe7  1  0.331  0.331  0.331  1.0
  Fe  Fe8  1  0.170  0.830  0.167  1.0
  Fe  Fe9  1  0.831  0.831  0.831  1.0
  Fe  Fe10  1  0.167  0.170  0.830  1.0
  Fe  Fe11  1  0.330  0.670  0.667  1.0
  Fe  Fe12  1  0.830  0.167  0.170  1.0
  Fe  Fe13  1  0.667  0.330  0.670  1.0
  Si  Si14  1  0.253  0.997  0.503  1.0
  Si  Si15  1  0.497  0.753  0.003  1.0
  Si  Si16  1  0.503  0.253  0.997  1.0
  Si  Si17  1  0.753  0.003  0.497  1.0
  Si  Si18  1  0.997  0.503  0.253  1.0
  Si  Si19  1  0.003  0.497  0.753  1.0
  S  S20  1  0.000  0.000  0.000  1.0
  S  S21  1  0.500  0.500  0.500  1.0
  O  O22  1  0.145  0.415  0.862  1.0
  O  O23  1  0.140  0.588  0.141  1.0
  O  O24  1  0.589  0.864  0.865  1.0
  O  O25  1  0.415  0.862  0.145  1.0
  O  O26  1  0.147  0.856  0.416  1.0
  O  O27  1  0.862  0.145  0.415  1.0
  O  O28  1  0.645  0.362  0.915  1.0
  O  O29  1  0.856  0.416  0.147  1.0
  O  O30  1  0.865  0.589  0.864  1.0
  O  O31  1  0.416  0.147  0.856  1.0
  O  O32  1  0.588  0.141  0.140  1.0
  O  O33  1  0.141  0.140  0.588  1.0
  O  O34  1  0.864  0.865  0.589  1.0
  O  O35  1  0.089  0.365  0.364  1.0
  O  O36  1  0.647  0.916  0.356  1.0
  O  O37  1  0.364  0.089  0.365  1.0
  O  O38  1  0.088  0.640  0.641  1.0
  O  O39  1  0.362  0.915  0.645  1.0
  O  O40  1  0.915  0.645  0.362  1.0
  O  O41  1  0.916  0.356  0.647  1.0
  O  O42  1  0.641  0.088  0.640  1.0
  O  O43  1  0.640  0.641  0.088  1.0
  O  O44  1  0.365  0.364  0.089  1.0
  O  O45  1  0.356  0.647  0.916  1.0
[/CIF]
.