Variable-Temperature Microcrystal X-ray Diffraction Studies of Negative Thermal Expansion in the Pure Silica Zeolite IFR
Luis A. Villaescusa; Philip Lightfoot; Simon J. Teat; Russell E. Morris; Journal of the American Chemical Society 123 (2001) 5453–5459; doi:10.1021/ja015797o

data_4115569
_publ_section_title
;
 Variable-Temperature Microcrystal X-ray Diffraction Studies of Negative
 Thermal Expansion in the Pure Silica Zeolite IFR
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5453
_journal_page_last               5459
_journal_paper_doi               10.1021/ja015797o
_journal_volume                  123
_journal_year                    2001
_chemical_formula_sum            'O64 Si32'
_chemical_formula_weight         1922.88
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           12
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-I 2y'
_symmetry_space_group_name_H-M   'I 1 2/m 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 102.196(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   18.6794(13)
_cell_length_b                   13.5313(10)
_cell_length_c                   7.6028(6)
_cell_measurement_temperature    30(2)
_cell_volume                     1878.3(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      30(2)
_diffrn_measured_fraction_theta_full 0.763
_diffrn_measured_fraction_theta_max 0.763
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_wavelength     0.69420
_diffrn_reflns_av_R_equivalents  0.0911
_diffrn_reflns_av_sigmaI/netI    0.1200
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            3988
_diffrn_reflns_theta_full        25.85
_diffrn_reflns_theta_max         25.85
_diffrn_reflns_theta_min         1.83
_exptl_absorpt_coefficient_mu    0.639
_exptl_absorpt_correction_T_max  0.9936
_exptl_absorpt_correction_T_min  0.9873
_exptl_crystal_density_diffrn    1.700
_exptl_crystal_F_000             960
_exptl_crystal_size_max          0.02
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.720
_refine_diff_density_min         -0.740
_refine_diff_density_rms         0.178
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     114
_refine_ls_number_reflns         1555
_refine_ls_number_restraints     36
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.1277
_refine_ls_R_factor_gt           0.0752
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0998P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1631
_refine_ls_wR_factor_ref         0.1864
_reflns_number_gt                970
_reflns_number_total             1555
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja015797o_s1_1.cif
_cod_data_source_block           IFR_30K
_cod_original_sg_symbol_H-M      'I 2/m'
_cod_database_code               4115569