data_global
_chemical_name_mineral 'Phenakite'
loop_
_publ_author_name
'Hazen R M'
'Au A Y'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 13 
_journal_year 1986
_journal_page_first 69
_journal_page_last 78
_publ_section_title
;
 High-pressure crystal chemistry of phenakite (Be2SiO4)
 and bertrandite (Be4Si2O7(OH)2)
 Sample: P = 1 bar
;
_database_code_amcsd 0007371
_chemical_formula_sum 'Be2 Si O4'
_cell_length_a 12.4704
_cell_length_b 12.4704
_cell_length_c 8.2504
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1111.134
_exptl_crystal_density_diffrn      2.962
_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   0.19410   0.21040   0.41550   0.00456
Be2   0.19410   0.21180   0.08410   0.00507
Si   0.19550   0.21155   0.74996   0.00177
O1   0.20950   0.08840   0.75030   0.00367
O2   0.33360   0.33320   0.75010   0.00329
O3   0.12250   0.21000   0.91460   0.00329
O4   0.12250   0.20900   0.58500   0.00355
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Be1 0.00561 0.00490 0.00334 0.00266 -0.00050 0.00032
Be2 0.00526 0.00632 0.00403 0.00325 0.00005 -0.00014
Si 0.00189 0.00236 0.00134 0.00124 0.00018 0.00023
O1 0.00585 0.00319 0.00297 0.00290 -0.00032 0.00018
O2 0.00284 0.00319 0.00376 0.00148 -0.00023 -0.00036
O3 0.00360 0.00526 0.00203 0.00290 0.00027 0.00018
O4 0.00319 0.00585 0.00197 0.00266 0.00005 0.00027