The structure described by Si2TeO7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Te(1)O6 octahedra,  a cornercorner with one Te(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-56°. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Te(1)O6 octahedra,  a cornercorner with one Te(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-56°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Te(2)O6 octahedra. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Te(1)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(7) is bonded in a single-bond geometry to one Si(1) atom. In the third O site, O(1) is bonded in a bent 120 degrees geometry to one Si(2) and one Te(2) atom. In the fourth O site, O(2) is bonded in a water-like geometry to one Te(1) and one Te(2) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Si(2) and one Te(1) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Si(1), one Te(1), and one Te(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si2TeO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.617
_cell_length_b   9.617
_cell_length_c   10.661
_cell_angle_alpha   58.959
_cell_angle_beta   58.959
_cell_angle_gamma   48.312
_symmetry_Int_Tables_number   1
_cell_volume   607.460
_cell_formula_units_Z   4
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
  Si  Si0  1  0.527  0.133  0.665  1.0
  Si  Si1  1  0.133  0.527  0.165  1.0
  Si  Si2  1  0.541  0.190  0.099  1.0
  Si  Si3  1  0.190  0.541  0.599  1.0
  Si  Si4  1  0.867  0.473  0.835  1.0
  Si  Si5  1  0.459  0.810  0.901  1.0
  Si  Si6  1  0.810  0.459  0.401  1.0
  Si  Si7  1  0.473  0.867  0.335  1.0
  Te  Te8  1  0.792  0.208  0.750  1.0
  Te  Te9  1  0.208  0.792  0.250  1.0
  Te  Te10  1  0.000  0.000  0.000  1.0
  Te  Te11  1  0.000  0.000  0.500  1.0
  O  O12  1  0.880  0.263  0.374  1.0
  O  O13  1  0.950  0.923  0.401  1.0
  O  O14  1  0.447  0.712  0.089  1.0
  O  O15  1  0.923  0.950  0.901  1.0
  O  O16  1  0.261  0.912  0.332  1.0
  O  O17  1  0.007  0.522  0.668  1.0
  O  O18  1  0.712  0.447  0.589  1.0
  O  O19  1  0.088  0.739  0.168  1.0
  O  O20  1  0.993  0.478  0.332  1.0
  O  O21  1  0.635  0.643  0.322  1.0
  O  O22  1  0.050  0.077  0.599  1.0
  O  O23  1  0.739  0.088  0.668  1.0
  O  O24  1  0.478  0.993  0.832  1.0
  O  O25  1  0.263  0.880  0.874  1.0
  O  O26  1  0.643  0.635  0.822  1.0
  O  O27  1  0.912  0.261  0.832  1.0
  O  O28  1  0.904  0.421  0.985  1.0
  O  O29  1  0.365  0.357  0.678  1.0
  O  O30  1  0.579  0.096  0.515  1.0
  O  O31  1  0.357  0.365  0.178  1.0
  O  O32  1  0.522  0.007  0.168  1.0
  O  O33  1  0.077  0.050  0.099  1.0
  O  O34  1  0.421  0.904  0.485  1.0
  O  O35  1  0.553  0.288  0.911  1.0
  O  O36  1  0.096  0.579  0.015  1.0
  O  O37  1  0.288  0.553  0.411  1.0
  O  O38  1  0.737  0.120  0.126  1.0
  O  O39  1  0.120  0.737  0.626  1.0
[/CIF]
.
The structure described by Si2TeO7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Te(1)O6 octahedra,  a cornercorner with one Te(2)O6 octahedra, and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 45-56°. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Te(1)O6 octahedra,  a cornercorner with one Te(2)O6 octahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-56°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Te(2)O6 octahedra. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Te(1)O6 octahedra. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(7) is bonded in a single-bond geometry to one Si(1) atom. In the third O site, O(1) is bonded in a bent 120 degrees geometry to one Si(2) and one Te(2) atom. In the fourth O site, O(2) is bonded in a water-like geometry to one Te(1) and one Te(2) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Si(2) and one Te(1) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Si(1), one Te(1), and one Te(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si2TeO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.617
_cell_length_b   9.617
_cell_length_c   10.661
_cell_angle_alpha   58.959
_cell_angle_beta   58.959
_cell_angle_gamma   48.312
_symmetry_Int_Tables_number   1
_cell_volume   607.460
_cell_formula_units_Z   4
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
  Si  Si0  1  0.527  0.133  0.665  1.0
  Si  Si1  1  0.133  0.527  0.165  1.0
  Si  Si2  1  0.541  0.190  0.099  1.0
  Si  Si3  1  0.190  0.541  0.599  1.0
  Si  Si4  1  0.867  0.473  0.835  1.0
  Si  Si5  1  0.459  0.810  0.901  1.0
  Si  Si6  1  0.810  0.459  0.401  1.0
  Si  Si7  1  0.473  0.867  0.335  1.0
  Te  Te8  1  0.792  0.208  0.750  1.0
  Te  Te9  1  0.208  0.792  0.250  1.0
  Te  Te10  1  0.000  0.000  0.000  1.0
  Te  Te11  1  0.000  0.000  0.500  1.0
  O  O12  1  0.880  0.263  0.374  1.0
  O  O13  1  0.950  0.923  0.401  1.0
  O  O14  1  0.447  0.712  0.089  1.0
  O  O15  1  0.923  0.950  0.901  1.0
  O  O16  1  0.261  0.912  0.332  1.0
  O  O17  1  0.007  0.522  0.668  1.0
  O  O18  1  0.712  0.447  0.589  1.0
  O  O19  1  0.088  0.739  0.168  1.0
  O  O20  1  0.993  0.478  0.332  1.0
  O  O21  1  0.635  0.643  0.322  1.0
  O  O22  1  0.050  0.077  0.599  1.0
  O  O23  1  0.739  0.088  0.668  1.0
  O  O24  1  0.478  0.993  0.832  1.0
  O  O25  1  0.263  0.880  0.874  1.0
  O  O26  1  0.643  0.635  0.822  1.0
  O  O27  1  0.912  0.261  0.832  1.0
  O  O28  1  0.904  0.421  0.985  1.0
  O  O29  1  0.365  0.357  0.678  1.0
  O  O30  1  0.579  0.096  0.515  1.0
  O  O31  1  0.357  0.365  0.178  1.0
  O  O32  1  0.522  0.007  0.168  1.0
  O  O33  1  0.077  0.050  0.099  1.0
  O  O34  1  0.421  0.904  0.485  1.0
  O  O35  1  0.553  0.288  0.911  1.0
  O  O36  1  0.096  0.579  0.015  1.0
  O  O37  1  0.288  0.553  0.411  1.0
  O  O38  1  0.737  0.120  0.126  1.0
  O  O39  1  0.120  0.737  0.626  1.0
[/CIF]
.