Vacancy pairing and superstructure in the high-pressure silicate K~1.5~Mg~2~Si~2~O~7~H~0.5~: a new potential host for potassium in the deep Earth
Welch, M. D.; Bindi, L.; Petříček, V.; Plášil, J.; Acta Crystallographica Section B 72 (2016) 822–827; doi:10.1107/S2052520616014049

data_2020661
_publ_section_title
;
 Vacancy pairing and superstructure in the high-pressure silicate
 K~1.5~Mg~2~Si~2~O~7~H~0.5~: a new potential host for potassium in the
 deep Earth
;
_journal_coeditor_code           XK5031SUP1
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section B'
_journal_page_first              822
_journal_page_last               827
_journal_paper_doi               10.1107/S2052520616014049
_journal_volume                  72
_journal_year                    2016
_chemical_formula_sum            'H0.5 K1.5 Mg2 O7 Si2'
_chemical_formula_weight         275.45
_space_group_IT_number           193
_symmetry_space_group_name_Hall  '-P 6c 2'
_symmetry_space_group_name_H-M   'P 63/m c m'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
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_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            2
_cell_length_a                   5.0535(3)
_cell_length_b                   5.0535(3)
_cell_length_c                   13.2229(6)
_cell_measurement_reflns_used    1268
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.8550
_cell_measurement_theta_min      4.6460
_cell_volume                     292.44(3)
_computing_cell_refinement       'CrysAlisPro,Version 1.171.35.19'
_computing_data_collection       'CrysAlisPro,Version 1.171.35.19'
_computing_data_reduction        'CrysAlisPro,Version 1.171.35.19'
_computing_molecular_graphics    Crystalmaker
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Excalibur EOS detector Agilent Technologies'
_diffrn_measurement_method       '1K CCD-based area detector'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0239
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_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            2759
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.32
_diffrn_reflns_theta_min         3.08
_diffrn_standards_interval_time  '120 min'
_exptl_absorpt_coefficient_mu    1.882
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6877
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    3.128
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             273
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.337
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_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     21
_refine_ls_number_reflns         143
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.451
_refine_ls_R_factor_all          0.0296
_refine_ls_R_factor_gt           0.0296
_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^)+(0.0307P)^2^+0.5285P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0827
_refine_ls_wR_factor_ref         0.0827
_reflns_number_gt                143
_reflns_number_total             143
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            xk5031sup1.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'multiscan' changed to
'multi-scan' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/IUCr/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 4268 2015-11-12 08:31:59Z antanas 

 Adding full bibliography for 2020661--2020662.cif.
;
_cod_original_cell_volume        292.45(3)
_cod_original_formula_sum        'K1.50 Mg2 O7 Si2 H0.5'
_cod_database_code               2020661