The material described by Na3CrBSiO7 crystallizes in the monoclinic Pm space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(1), one O(4), and two equivalent O(11) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(12) atoms. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(7), one O(9), and two equivalent O(11) atoms. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(10), one O(2), one O(4), one O(6), one O(8), and two equivalent O(12) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(4), one O(6), one O(7), and two equivalent O(12) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(3), one O(5), one O(8), one O(9), and two equivalent O(11) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(7), and two equivalent O(11) atoms to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. In the second Si site, Si(2) is bonded to one O(8), one O(9), and two equivalent O(12) atoms to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-44°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(3), and one B(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(4), and one B(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(3), one Cr(2), and one B(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(4), one Cr(1), and one B(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(2), and one B(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Na(4), one Cr(1), and one B(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Na(4), one Cr(2), and one Si(2) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to two equivalent Na(3), one Cr(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to two equivalent Na(4), one Cr(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(3), one Cr(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(4), one Cr(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Na3CrSiBO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.323
_cell_length_b   8.959
_cell_length_c   6.483
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.883
_symmetry_Int_Tables_number   1
_cell_volume   308.968
_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
  Na  Na0  1  0.763  0.080  0.250  1.0
  Na  Na1  1  0.238  0.920  0.750  1.0
  Na  Na2  1  0.257  0.261  0.008  1.0
  Na  Na3  1  0.257  0.261  0.492  1.0
  Na  Na4  1  0.743  0.739  0.508  1.0
  Na  Na5  1  0.743  0.739  0.992  1.0
  Cr  Cr6  1  0.212  0.667  0.250  1.0
  Cr  Cr7  1  0.788  0.333  0.750  1.0
  Si  Si8  1  0.717  0.428  0.250  1.0
  Si  Si9  1  0.282  0.572  0.750  1.0
  B  B10  1  0.729  0.067  0.750  1.0
  B  B11  1  0.272  0.933  0.250  1.0
  O  O12  1  0.313  0.080  0.250  1.0
  O  O13  1  0.686  0.921  0.750  1.0
  O  O14  1  0.965  0.132  0.750  1.0
  O  O15  1  0.036  0.867  0.250  1.0
  O  O16  1  0.537  0.181  0.750  1.0
  O  O17  1  0.464  0.819  0.250  1.0
  O  O18  1  0.416  0.477  0.250  1.0
  O  O19  1  0.583  0.524  0.750  1.0
  O  O20  1  0.106  0.426  0.750  1.0
  O  O21  1  0.892  0.575  0.250  1.0
  O  O22  1  0.784  0.319  0.050  1.0
  O  O23  1  0.784  0.319  0.450  1.0
  O  O24  1  0.216  0.681  0.550  1.0
  O  O25  1  0.216  0.681  0.950  1.0
[/CIF]
.
The material described by Na3CrBSiO7 crystallizes in the monoclinic Pm space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(1), one O(4), and two equivalent O(11) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(12) atoms. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(7), one O(9), and two equivalent O(11) atoms. In the fourth Na site, Na(4) is bonded in a 7-coordinate geometry to one O(10), one O(2), one O(4), one O(6), one O(8), and two equivalent O(12) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(4), one O(6), one O(7), and two equivalent O(12) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(3), one O(5), one O(8), one O(9), and two equivalent O(11) atoms to form CrO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(5) atom. In the second B site, B(2) is bonded in a trigonal planar geometry to one O(1), one O(4), and one O(6) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(7), and two equivalent O(11) atoms to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-44°. In the second Si site, Si(2) is bonded to one O(8), one O(9), and two equivalent O(12) atoms to form SiO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-44°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(3), and one B(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(4), and one B(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(3), one Cr(2), and one B(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(4), one Cr(1), and one B(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(2), and one B(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent Na(4), one Cr(1), and one B(2) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to two equivalent Na(3), one Cr(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Na(4), one Cr(2), and one Si(2) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to two equivalent Na(3), one Cr(2), and one Si(2) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to two equivalent Na(4), one Cr(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(3), one Cr(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Na(2), two equivalent Na(4), one Cr(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_Na3CrSiBO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.323
_cell_length_b   8.959
_cell_length_c   6.483
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   87.883
_symmetry_Int_Tables_number   1
_cell_volume   308.968
_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
  Na  Na0  1  0.763  0.080  0.250  1.0
  Na  Na1  1  0.238  0.920  0.750  1.0
  Na  Na2  1  0.257  0.261  0.008  1.0
  Na  Na3  1  0.257  0.261  0.492  1.0
  Na  Na4  1  0.743  0.739  0.508  1.0
  Na  Na5  1  0.743  0.739  0.992  1.0
  Cr  Cr6  1  0.212  0.667  0.250  1.0
  Cr  Cr7  1  0.788  0.333  0.750  1.0
  Si  Si8  1  0.717  0.428  0.250  1.0
  Si  Si9  1  0.282  0.572  0.750  1.0
  B  B10  1  0.729  0.067  0.750  1.0
  B  B11  1  0.272  0.933  0.250  1.0
  O  O12  1  0.313  0.080  0.250  1.0
  O  O13  1  0.686  0.921  0.750  1.0
  O  O14  1  0.965  0.132  0.750  1.0
  O  O15  1  0.036  0.867  0.250  1.0
  O  O16  1  0.537  0.181  0.750  1.0
  O  O17  1  0.464  0.819  0.250  1.0
  O  O18  1  0.416  0.477  0.250  1.0
  O  O19  1  0.583  0.524  0.750  1.0
  O  O20  1  0.106  0.426  0.750  1.0
  O  O21  1  0.892  0.575  0.250  1.0
  O  O22  1  0.784  0.319  0.050  1.0
  O  O23  1  0.784  0.319  0.450  1.0
  O  O24  1  0.216  0.681  0.550  1.0
  O  O25  1  0.216  0.681  0.950  1.0
[/CIF]
.