Effect of cationic substitution on the double-well hydrogen-bond potential in [K<sub>1-x</sub>(NH<sub>4</sub>)<sub>x</sub>]<sub>3</sub>H(SO<sub>4</sub>)<sub>2</sub> proton conductors: a single-crystal neutron diffraction study.
Choudhury, R. R.; Chitra, R.; Selezneva, E. V.; Makarova, I. P.; Acta crystallographica Section B, Structural science, crystal engineering and materials 73 (2017) 863–867; doi:10.1107/S2052520617008642

data_2311741
_publ_section_title
;
 Effect of cationic substitution on the double-well hydrogen-bond
 potential in
 [K<sub>1-x</sub>(NH<sub>4</sub>)<sub>x</sub>]<sub>3</sub>H(SO<sub>4</sub>)<sub>2</sub>
 proton conductors: a single-crystal neutron diffraction study.
;
_journal_coeditor_code           RA5020SUP1
_journal_issue                   'Pt 5'
_journal_name_full
'Acta crystallographica Section B, Structural science, crystal engineering and materials'
_journal_page_first              863
_journal_page_last               867
_journal_paper_doi               10.1107/S2052520617008642
_journal_volume                  73
_journal_year                    2017
_chemical_formula_sum            'H K2.91 N0.09 O8 S2'
_chemical_formula_weight         616.34
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_H-M   'C 1 2/c 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                 102.990(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   14.692(2)
_cell_length_b                   5.6810(10)
_cell_length_c                   9.7760(10)
_cell_measurement_reflns_used    50
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      44.19
_cell_measurement_theta_min      3.99
_cell_volume                     795.1(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.960
_diffrn_measured_fraction_theta_max 0.960
_diffrn_radiation_monochromator  Copper
_diffrn_radiation_source         'Dhruva reactor'
_diffrn_radiation_type           neutron
_diffrn_radiation_wavelength     0.99600
_diffrn_reflns_av_R_equivalents  0.0404
_diffrn_reflns_av_sigmaI/netI    0.1195
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            1211
_diffrn_reflns_theta_full        44.19
_diffrn_reflns_theta_max         44.19
_diffrn_reflns_theta_min         3.99
_exptl_crystal_colour            transparent
_exptl_crystal_density_diffrn    2.574
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             240
_exptl_crystal_size_max          2X2X2
_refine_diff_density_max         0.227
_refine_diff_density_min         -0.226
_refine_diff_density_rms         0.030
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.104
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     65
_refine_ls_number_reflns         1094
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.104
_refine_ls_R_factor_all          0.2401
_refine_ls_R_factor_gt           0.1391
_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^)+(0.0853P)^2^+0.8246P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3037
_refine_ls_wR_factor_ref         0.3868
_reflns_number_gt                606
_reflns_number_total             1094
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ra5020sup1.cif
_cod_data_source_block           I
_cod_original_cell_volume        795.08(19)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2311741