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 = 0 GPa
;
_database_code_amcsd 0008404
_chemical_formula_sum 'Mg7 Si2 O14 H6'
_cell_length_a 7.8563
_cell_length_b 7.8563
_cell_length_c 9.5642
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 511.229
_exptl_crystal_density_diffrn      2.965
_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   0.00988
Mg2   0.22520   0.24380   0.11270   0.00988
Mg3   0.33333   0.66667   0.10290   0.00988
Si1   0.66667   0.33333   0.17410   0.00849
Si2   0.00000   0.00000   0.40180   0.00849
O1   0.20010   0.02740  -0.02400   0.00937
O2   0.47660   0.09880   0.48440   0.00937
O3   0.45380   0.29470   0.23200   0.00937
O4   0.17040   0.43670   0.23980   0.00937
O5   0.66667   0.33333   0.00000   0.00937
O6   0.00000   0.00000   0.23230   0.00937
HD1   0.45500   0.16100   0.40500   0.03293
HD2   0.03800   0.36100   0.24000   0.03293