data_global
_chemical_name_mineral 'Amesite'
loop_
_publ_author_name
'Steadman R'
'Nuttall P M'
_journal_name_full 'Acta Crystallographica'
_journal_volume 15 
_journal_year 1962
_journal_page_first 510
_journal_page_last 511
_publ_section_title
;
 The crystal structure of amesite
 Note: polytype 6R
;
_database_code_amcsd 0018742
_chemical_compound_source 'Saranovskaye, USSR'
_chemical_formula_sum 'Mg2 Al2 Si O9 H4'
_cell_length_a 5.31
_cell_length_b 5.31
_cell_length_c 42.1
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 1028.020
_exptl_crystal_density_diffrn      2.701
_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'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
MgY1   0.33300   0.00000   0.24500   0.66700
AlY1   0.33300   0.00000   0.24500   0.33300
MgY2   0.66700   0.00000   0.07800   0.66600
AlY2   0.66700   0.00000   0.07800   0.33400
SiX1   0.00000   0.00000   0.51400   0.50000
AlX1   0.00000   0.00000   0.51400   0.50000
SiX2   0.00000   0.00000   0.84700   0.50000
AlX2   0.00000   0.00000   0.84700   0.50000
SiX3   0.00000   0.00000   0.34700   0.50000
AlX3   0.00000   0.00000   0.34700   0.50000
SiX4   0.00000   0.00000   0.68100   0.50000
AlX4   0.00000   0.00000   0.68100   0.50000
O1   0.00000   0.00000   0.55400   1.00000
O2   0.00000   0.00000   0.88700   1.00000
O3   0.00000   0.00000   0.38700   1.00000
O4   0.00000   0.00000   0.72100   1.00000
O5   0.55000   0.00000   0.16700   1.00000
O6   0.45000   0.00000   0.00000   1.00000
O-H1   0.66700   0.00000   0.26900   1.00000
O-H2   0.33300   0.00000   0.10200   1.00000
O-H3   0.00000   0.00000   0.22100   1.00000
O-H4   0.00000   0.00000   0.05400   1.00000