data_global
_chemical_name_mineral 'Sphaerobertrandite'
loop_
_publ_author_name
'Pekov I V'
'Chukanov N V'
'Larsen A O'
'Merlino S'
'Pasero M'
'Pushcharovsky D Y'
'Ivaldi G'
'Zadov A E'
'Grishin V G'
'Asheim A'
'Tafto J'
'Chistyakova N I'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 15 
_journal_year 2003
_journal_page_first 157
_journal_page_last 166
_publ_section_title
;
 Sphaerobertrandite, Be3SiO4(OH)2: new data, crystal structure and genesis
;
_database_code_amcsd 0006960
_chemical_formula_sum 'Be3 Si O6 H2'
_cell_length_a 5.082
_cell_length_b 4.640
_cell_length_c 17.696
_cell_angle_alpha 90
_cell_angle_beta 106.13
_cell_angle_gamma 90
_cell_volume 400.853
_exptl_crystal_density_diffrn      2.537
_symmetry_space_group_name_H-M 'P 1 21/c 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,1/2-y,1/2+z'
  '-x,1/2+y,1/2-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Be1   0.29000   0.41600   0.11980   0.00600
Be2   0.62900   0.08900   0.96040   0.00700
Be3   0.11000   0.91700   0.29240   0.00600
Si   0.02740   0.41950   0.37550   0.00730
O1   0.02300   0.57400   0.14300   0.00800
O2   0.04500   0.57100   0.29330   0.00800
O3   0.22800   0.06900   0.09900   0.00100
O4   0.69700   0.97400   0.05400   0.00800
O-H5   0.30700   0.57500   0.04130   0.01100
O-H6   0.55700   0.46500   0.19390   0.01300