data_global
_chemical_name_mineral 'Protoenstatite'
loop_
_publ_author_name
'Yang H'
'Ghose S'
_journal_name_full 'Physics and Chemistry of Minerals'
_journal_volume 22 
_journal_year 1995
_journal_page_first 300
_journal_page_last 310
_publ_section_title
;
 High temperature single crystal X-ray diffraction studies
 of the ortho-proto phase transition in enstatite, Mg2Si2O6 at 1360 K
 Sample: T = 1400 K
;
_database_code_amcsd 0007924
_chemical_formula_sum 'Mg Si O3'
_cell_length_a 9.315
_cell_length_b 8.899
_cell_length_c 5.365
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 444.727
_exptl_crystal_density_diffrn      2.999
_symmetry_space_group_name_H-M 'P b c n'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'x,-y,1/2+z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,z'
  '1/2+x,1/2-y,-z'
  '1/2+x,1/2+y,1/2-z'
  '1/2-x,1/2-y,1/2+z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Mg1   0.00000   0.09990   0.75000   0.03464
Mg2   0.00000   0.26120   0.25000   0.04234
SiA   0.29310   0.08980   0.07410   0.02271
O1A   0.11890   0.09370   0.07870   0.02908
O2A   0.37610   0.24580   0.06610   0.04193
O3A   0.34880   0.98520   0.30740   0.04074
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 0.04660 0.02848 0.02858 0.00000 -0.00911 0.00000
Mg2 0.05758 0.03450 0.03500 0.00000 -0.00152 0.00000
SiA 0.02681 0.02086 0.02056 -0.00378 -0.00076 0.00145
O1A 0.02637 0.03611 0.02479 -0.00462 -0.00152 -0.00411
O2A 0.05495 0.02929 0.04156 -0.02730 0.00532 -0.00556
O3A 0.03824 0.05617 0.02785 0.00252 -0.00405 0.01838