Mixed Alkali Systems: Structure and ^29^Si MASNMR of Li~2~Si~2~O~5~ and K~2~Si~2~O~5~
de Jong, B. H. W. S.; Supèr, H. T. J.; Spek, A. L.; Veldman, N.; Nachtegaal, G.; Fischer, J. C.; Acta Crystallographica Section B 54 (1998) 568–577; doi:10.1107/S0108768198001062

data_2003027
_publ_section_title
;
 Mixed Alkali Systems: Structure and ^29^Si MASNMR of Li~2~Si~2~O~5~
 and K~2~Si~2~O~5~
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              568
_journal_page_last               577
_journal_paper_doi               10.1107/S0108768198001062
_journal_volume                  54
_journal_year                    1998
_chemical_formula_moiety         'Li2 Si2 O5'
_chemical_formula_sum            'Li2 O5 Si2'
_chemical_formula_weight         150.05
_chemical_name_systematic
;
 Lithium Disilicate
;
_space_group_IT_number           37
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'C 2 -2c'
_symmetry_space_group_name_H-M   'C c c 2'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.807(2)
_cell_length_b                   14.582(7)
_cell_length_c                   4.773(3)
_cell_measurement_reflns_used    10
_cell_measurement_temperature    293
_cell_measurement_theta_max      13
_cell_measurement_theta_min      11
_cell_volume                     404.2(3)
_computing_publication_material  'PLATON (Spek, 1990)'
_diffrn_ambient_temperature      293
_diffrn_measurement_device_type  CAD4-T
_diffrn_measurement_method       \w-2\q-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0639
_diffrn_reflns_av_sigmaI/netI    0.0383
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            967
_diffrn_reflns_theta_max         27.46
_diffrn_reflns_theta_min         2.79
_diffrn_standards_decay_%        1
_diffrn_standards_interval_time  60
_diffrn_standards_number         1
_exptl_absorpt_coefficient_mu    0.78
_exptl_absorpt_correction_T_max  0.991
_exptl_absorpt_correction_T_min  0.789
_exptl_absorpt_correction_type   'analytical (Spek, 1990)'
_exptl_absorpt_process_details   'de Meulenaar & Tompa'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    2.466
_exptl_crystal_density_meas      ?
_exptl_crystal_description       'thin plate'
_exptl_crystal_F_000             296
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.012
_refine_diff_density_max         0.818
_refine_diff_density_min         -0.579
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.133
_refine_ls_hydrogen_treatment    'H-atom refinement: see text '
_refine_ls_matrix_type           full
_refine_ls_number_parameters     42
_refine_ls_number_reflns         261
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.130
_refine_ls_R_factor_all          0.0464
_refine_ls_R_factor_gt           0.0450
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0883P)^2^+0.0491P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1138
_reflns_number_gt                249
_reflns_number_total             261
_reflns_threshold_expression     'I > 2 \s(I)'
_cod_data_source_file            na0083.cif
_cod_data_source_block           s737a
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'w =
1/[\s^2^(Fo^2^)+(0.0883P)^2^+0.0491P] where P=(Fo^2^+2Fc^2^)/3' 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^(Fo^2^)+(0.0883P)^2^+0.0491P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_Hall     'C 2 -c'
_cod_database_code               2003027