Transferability of Empirical Force Fields in Silicates: Lattice-Dynamical Evaluation of Atomic Displacement Parameters and Thermodynamic Properties for the Al~2~OSiO~4~ Polymorphs
Pilati, T.; Demartin, F.; Gramaccioli, C. M.; Acta Crystallographica Section B 53 (1997) 82–94; doi:10.1107/S0108768196011482

data_2101671
_publ_section_title
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 Transferability of Empirical Force Fields in Silicates:
 Lattice-Dynamical Evaluation of Atomic Displacement Parameters and
 Thermodynamic Properties for the Al~2~OSiO~4~ Polymorphs
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_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              82
_journal_page_last               94
_journal_paper_doi               10.1107/S0108768196011482
_journal_volume                  53
_journal_year                    1997
_chemical_formula_sum            'Al2 O5 Si'
_space_group_IT_number           58
_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
_cell_volume                     342.73(5)
_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_details     'w = 1/\s^2^(F)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_obs         0.018
_reflns_number_observed          875
_reflns_number_total             1135
_reflns_observed_criterion       'I>3\s(I), \q>15\%'
_cod_data_source_file            cr0515.cif
_cod_data_source_block           cr0515a
_cod_depositor_comments
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The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w = 1/\s^2^(F)' was changed to
'calc'. New tag '_refine_ls_weighting_details' was created. The value
of the new tag was set to 'w = 1/\s^2^(F)'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
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_cod_database_code               2101671