data_PCOD7002756
_publ_section_title
;
Structure prediction by GRINSP 2.00 - 2006 (A. Le Bail)
Si2B2O7        PCOD7002756 R =  0.0050
Probable space group: P -6 2 M
;
_chemical_formula_sum  "Si2 B2 O7"
_cell_formula_units_Z    3
_cell_length_a         15.4844
_cell_length_b         15.4844
_cell_length_c          5.0087
_cell_angle_alpha     90.000
_cell_angle_beta      90.000
_cell_angle_gamma    120.000
_cell_volume          1040.03
_symmetry_space_group_name_H-M   "P 1"
_symmetry_Int_Tables_number  1
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si1      0.21200   0.57084   0.01290
Si2      0.42688   0.64087  -0.00754
Si3      0.35738   0.78699   0.00002
Si4      0.57228   0.21450   0.00082
Si5      0.64912   0.43124   0.00293
Si6      0.78939   0.35423  -0.01012
B7      0.10045   0.51339   0.51306
B8     -0.50503  -0.40576   0.48942
B9      0.40919  -0.09936   0.50045
B10      0.51465   0.10347   0.49899
B11     -0.39770  -0.50264   0.50316
B12     -0.10050   0.40641   0.48796
O1      0.30988   0.55918   0.00387
O2      0.24832   0.68840   0.01002
O3      0.15021   0.52004   0.28077
O4      0.14436   0.51807  -0.24543
O5      0.43826   0.75032  -0.00256
O6      0.48267   0.62875   0.24842
O7      0.47509   0.62740  -0.27742
O8      0.37338   0.85510   0.25853
O9      0.36850   0.84911  -0.26764
O10      0.56482   0.31477   0.00507
O11      0.68879   0.24664   0.00350
O12      0.51758   0.14781   0.25952
O13      0.52104   0.15274  -0.26752
O14      0.75668   0.43823  -0.00440
O15      0.64017   0.48407   0.26945
O16      0.63716   0.48537  -0.25635
O17      0.85849   0.36736   0.24352
O18      0.84794   0.36268  -0.28234
O19     -0.00077   0.47572   0.50412
O20     -0.45702  -0.46001   0.49743
O21      0.47369   0.00176   0.50750
#
#_symmetry_space_group_name_H-M  P -6 2 M
#_symmetry_Int_Tables_number  189
#
#   Starting Wyckoff positions:
#
#    1     6j     0.1794   0.5315   0.0000
#    2     6k     0.1023   0.4891   0.5000
#
#   Coordination Sequence :
#
# PCOD7002756 Si2B2O7         R =  0.0050  189
#   2
#   6  6
#    4   8  13  20  32  40  50  68   0   0
#    3   8  14  20  26  40  56  68   0   0
#
#_framework_density   11.54
#
