data_global
_chemical_name_mineral 'Phase-A'
loop_
_publ_author_name
'Kagi H'
'Parise J B'
'Cho H'
'Rossman G R'
'Loveday J S'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 27 
_journal_year 2000
_journal_page_first 225
_journal_page_last 233
_publ_section_title
;
 Hydrogen bonding interactions in phase A [Mg7Si2O8(OH)6]
 at ambient and high pressure
 Sample: P = 3.2 GPa
;
_database_code_amcsd 0008405
_chemical_formula_sum 'Mg7 Si2 O14 H6'
_cell_length_a 7.7972
_cell_length_b 7.7972
_cell_length_c 9.5071
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 500.560
_exptl_crystal_density_diffrn      3.028
_symmetry_space_group_name_H-M 'P 63'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x-y,x,1/2+z'
  '-y,x-y,z'
  '-x,-y,1/2+z'
  '-x+y,-x,z'
  'y,-x+y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Mg1   0.37220   0.45470   0.38570   0.00355
Mg2   0.22520   0.24380   0.11270   0.00355
Mg3   0.33333   0.66667   0.10290   0.00355
Si1   0.66667   0.33333   0.17410   0.00215
Si2   0.00000   0.00000   0.40180   0.00215
O1   0.20010   0.02740  -0.02400   0.00317
O2   0.47660   0.09880   0.48440   0.00317
O3   0.45380   0.29470   0.23200   0.00317
O4   0.17040   0.43670   0.23980   0.00317
O5   0.66667   0.33333   0.00000   0.00317
O6   0.00000   0.00000   0.23230   0.00317
HD1   0.45400   0.16500   0.40000   0.01874
HD2   0.03200   0.36300   0.23300   0.01874