#------------------------------------------------------------------------------
#$Date: 2011-09-17 21:27:16 +0100 (Sat, 17 Sep 2011) $
#$Revision: 26029 $
#$URL: svn://www.crystallography.net/cod/cif/2/2101671.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/. The original data for this entry
# were provided by IUCr Journals, http://journals.iucr.org/.
#
# The file may be used within the scientific community so long as
# proper attribution is given to the journal article from which the
# data were obtained.
#
data_2101671
loop_
_publ_author_name
'Pilati, T.'
'Demartin, F.'
'Gramaccioli, C. M.'
_publ_section_title
;
 Transferability of Empirical Force Fields in Silicates:
 Lattice-Dynamical Evaluation of Atomic Displacement Parameters and
 Thermodynamic Properties for the Al~2~OSiO~4~ Polymorphs
;
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              82
_journal_page_last               94
_journal_volume                  53
_journal_year                    1997
_chemical_formula_sum            'Al2 O5 Si'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2 2n'
_symmetry_space_group_name_H-M   'P n n m'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90.0
_cell_angle_beta                 90.0
_cell_angle_gamma                90.0
_cell_formula_units_Z            4
_cell_length_a                   7.7992(6)
_cell_length_b                   7.9050(6)
_cell_length_c                   5.5591(5)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    295(2)
_cell_measurement_theta_max      17.3
_cell_measurement_theta_min      16.9
_diffrn_measurement_device       'Nonius CAD-4'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.013
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2388
_diffrn_reflns_theta_max         40.0
_exptl_absorpt_correction_T_max  1.06
_exptl_absorpt_correction_T_min  0.92
_exptl_absorpt_correction_type   'DIFABS (Walker & Stuart, 1983)'
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.4
_refine_ls_extinction_coef       8.9E-6
_refine_ls_extinction_method     'Stout & Jensen (1968)'
_refine_ls_goodness_of_fit_obs   0.938
_refine_ls_number_reflns         875
_refine_ls_R_factor_obs          0.014
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme      'w = 1/\s^2^(F)'
_refine_ls_wR_factor_obs         0.018
_reflns_number_observed          875
_reflns_number_total             1135
_reflns_observed_criterion       'I>3\s(I), \q>15\%'
_[local]_cod_data_source_file    cr0515.cif
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
x,y,-z
1/2+x,1/2-y,1/2+z
1/2-x,1/2+y,1/2+z
-x,-y,-z
-x,-y,z
1/2-x,1/2+y,1/2-z
1/2+x,1/2-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
Si .24606(3) .25217(3) .0 .0038
Al1 .0 .0 .24196(4) .0052
Al2 .37054(3) .13900(3) .5 .0042
OA .42326(8) .36293(7) .5 .0054
OB .42438(8) .36293(7) .0 .0053
OC .10280(7) .40022(7) .0 .0071
OD .23064(5) .13397(5) .23948(8) .0058
_cod_database_code 2101671