data_global
_chemical_name_mineral 'Phase-A'
loop_
_publ_author_name
'Horiuchi H'
'Morimoto N'
'Yamamoto K'
'Akimoto S I'
_journal_name_full 'American Mineralogist'
_journal_volume 64 
_journal_year 1979
_journal_page_first 593
_journal_page_last 598
_publ_section_title
;
 Crystal structure of 2Mg2SiO4.3Mg(OH)2, a new high-pressure structure type
;
_database_code_amcsd 0000737
_chemical_formula_sum 'Mg7 Si2 O14'
_cell_length_a 7.8603
_cell_length_b 7.8603
_cell_length_c 9.5730
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 512.220
_exptl_crystal_density_diffrn      2.920
_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
Mg1   0.37220   0.45470   0.38570
Mg2   0.22520   0.24380   0.11270
Mg3   0.33333   0.66667   0.10290
Si1   0.66667   0.33333   0.17410
Si2   0.00000   0.00000   0.40180
O1   0.20010   0.02740  -0.02400
O2   0.47660   0.09880   0.48440
O3   0.45380   0.29470   0.23200
O4   0.17040   0.43670   0.23980
O5   0.66667   0.33333   0.00000
O6   0.00000   0.00000   0.23230
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
Mg1 0.00678 0.00685 0.00673 0.00293 -0.00155 0.00017
Mg2 0.00683 0.00568 0.00585 0.00298 -0.00129 -0.00109
Mg3 0.00664 0.00664 0.00617 0.00333 0.00000 0.00000
Si1 0.00460 0.00460 0.00339 0.00230 0.00000 0.00000
Si2 0.00479 0.00479 0.00325 0.00239 0.00000 0.00000
O1 0.00589 0.00563 0.00548 0.00277 -0.00020 -0.00033
O2 0.00751 0.00629 0.00631 0.00350 0.00013 -0.00040
O3 0.00514 0.00941 0.00631 0.00385 -0.00053 -0.00023
O4 0.00688 0.00657 0.00817 0.00340 0.00069 0.00076
O5 0.00655 0.00655 0.00557 0.00326 0.00000 0.00000
O6 0.00859 0.00859 0.00255 0.00430 0.00000 0.00000