data_global
_chemical_name_mineral 'Phenakite'
loop_
_publ_author_name
'Hazen R M'
'Finger L W'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 14 
_journal_year 1987
_journal_page_first 426
_journal_page_last 434
_publ_section_title
;
 High-temperature crystal chemistry of phenakite (Be2SiO4) and
 Chrysoberyl (BeAl2O4)
 Sample: T = 490 C
;
_database_code_amcsd 0007441
_chemical_formula_sum 'Be2 Si O4'
_cell_length_a 12.4647
_cell_length_b 12.4647
_cell_length_c 8.2515
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1110.266
_exptl_crystal_density_diffrn      2.964
_symmetry_space_group_name_H-M 'R -3'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '2/3+x,1/3+y,1/3+z'
  '1/3+x,2/3+y,2/3+z'
  'y,-x+y,-z'
  '2/3+y,1/3-x+y,1/3-z'
  '1/3+y,2/3-x+y,2/3-z'
  '-x+y,-x,z'
  '2/3-x+y,1/3-x,1/3+z'
  '1/3-x+y,2/3-x,2/3+z'
  '-x,-y,-z'
  '2/3-x,1/3-y,1/3-z'
  '1/3-x,2/3-y,2/3-z'
  '-y,x-y,z'
  '2/3-y,1/3+x-y,1/3+z'
  '1/3-y,2/3+x-y,2/3+z'
  'x-y,x,-z'
  '2/3+x-y,1/3+x,1/3-z'
  '1/3+x-y,2/3+x,2/3-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Be1   0.19445   0.21063   0.41563   0.01115
Be2   0.19380   0.21103   0.08446   0.01089
Si   0.19546   0.21158   0.74992   0.00659
O1   0.20996   0.08869   0.75036   0.01013
O2   0.33341   0.33297   0.74979   0.00912
O3   0.12248   0.20986   0.91459   0.00988
O4   0.12233   0.20871   0.58547   0.00988