data_global
_amcsd_formula_title 'Al3Si2O7(OH)3'
loop_
_publ_author_name
'Daniels P'
'Wunder B'
_journal_name_full 'European Journal of Mineralogy'
_journal_volume 8 
_journal_year 1996
_journal_page_first 1283
_journal_page_last 1292
_publ_section_title
;
 Al3Si2O7(OH)3, phase Pi (formerly piezotite): Crystal structure
 of a synthetic high-pressure silicate rediscovered
;
_database_code_amcsd 0006634
_chemical_formula_sum 'Al3 Si2 O10 H3'
_cell_length_a 6.0885
_cell_length_b 7.2832
_cell_length_c 7.7234
_cell_angle_alpha 115.71
_cell_angle_beta 88.85
_cell_angle_gamma 92.89
_cell_volume 308.186
_exptl_crystal_density_diffrn      3.234
_symmetry_space_group_name_H-M 'P 1'
loop_
_space_group_symop_operation_xyz
  '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
Al1  -0.28410   0.25270  -0.00760   0.00500
Al2   0.28410  -0.25270   0.00760   0.00500
Al3  -0.35440   0.35030   0.39510   0.00400
Al4   0.34940  -0.34770  -0.39280   0.00400
Al5   0.14450  -0.15110   0.39320   0.00390
Al6  -0.15010   0.15090  -0.39890   0.00390
Si1   0.36270   0.27540  -0.29230   0.00340
Si2  -0.36830  -0.27370   0.28720   0.00340
Si3  -0.14450  -0.22620  -0.29600   0.00350
Si4   0.13580   0.21800   0.29240   0.00350
O1  -0.30400   0.48840   0.23060   0.00450
O2   0.28780  -0.49330  -0.22670   0.00450
O3   0.20030  -0.01410   0.23110   0.00380
O4  -0.22180   0.00620  -0.23340   0.00380
O5  -0.37390   0.13990   0.15350   0.00400
O6   0.34780  -0.13530  -0.15180   0.00400
O7   0.12680  -0.36030   0.14960   0.00450
O8  -0.15130   0.36420  -0.15370   0.00450
O9   0.42960   0.23880  -0.10470   0.00500
O10  -0.43870  -0.25810   0.09480   0.00500
O11  -0.07970  -0.24460  -0.09620   0.00510
O12   0.05590   0.24240   0.09990   0.00510
O13  -0.43400   0.20710  -0.44800   0.00280
O14   0.41950  -0.22760   0.43320   0.00280
O15   0.06490  -0.28670  -0.43550   0.00430
O16  -0.07830   0.27810   0.43820   0.00430
O17   0.33540   0.38580   0.40060   0.00380
O18  -0.34740  -0.39320  -0.39430   0.00380
O19  -0.16340  -0.11360   0.40130   0.00350
O20   0.15450   0.11050  -0.39120   0.00350
H1   0.48300   0.08810   0.17960 ?
H2  -0.50520  -0.08700  -0.17970 ?
H3  -0.01450  -0.40990   0.17620 ?
H4  -0.00640   0.41120  -0.17780 ?
H5  -0.20200  -0.24920  -0.03110 ?
H6   0.18210   0.24120   0.03080 ?