Cyclic Water Pentamers in <small>L</small>-Leucyl-<small>L</small>-alanine Tetrahydrate
Görbitz, Carl Henrik; Acta Crystallographica Section C 53 (1997) 736–739; doi:10.1107/S0108270196015946

data_2006172
_publ_section_title
;
 Cyclic Water Pentamers in
 <small>L</small>-Leucyl-<small>L</small>-alanine Tetrahydrate
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              736
_journal_page_last               739
_journal_paper_doi               10.1107/S0108270196015946
_journal_volume                  53
_journal_year                    1997
_chemical_formula_iupac          'C9 H18 N2 O3 , 4H2 O'
_chemical_formula_sum            'C9 H26 N2 O7'
_chemical_formula_weight         274.32
_chemical_name_systematic
;
 L-leucyl-L-alanine tetrahydrate
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.1863(2)
_cell_length_b                   12.5481(4)
_cell_length_c                   19.8831(6)
_cell_measurement_reflns_used    19345
_cell_measurement_temperature    150(2)
_cell_volume                     1543.45(8)
_computing_cell_refinement       'SAINT (Siemens, 1995)'
_computing_data_collection       'SMART (Siemens, 1995)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 1994)'
_diffrn_ambient_temperature      150(2)
_diffrn_measurement_device       'Siemens SMART CCD diffractometer'
_diffrn_measurement_method
'Sets of exsposures each taken over 0.6\% \w rotation'
_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  0.0251
_diffrn_reflns_av_sigmaI/netI    0.0268
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            23659
_diffrn_reflns_theta_max         38.24
_diffrn_reflns_theta_min         1.92
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  0.990
_exptl_absorpt_correction_T_min  0.946
_exptl_absorpt_correction_type   'multi-scan (SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.181
_exptl_crystal_density_meas      ?
_exptl_crystal_description       Block
_exptl_crystal_F_000             600
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.348
_refine_diff_density_min         -0.164
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.142
_refine_ls_goodness_of_fit_obs   1.137
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     224
_refine_ls_number_reflns         7987
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.147
_refine_ls_restrained_S_obs      1.137
_refine_ls_R_factor_all          0.0455
_refine_ls_R_factor_obs          .0380
_refine_ls_shift/esd_max         -0.009
_refine_ls_shift/esd_mean        0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0365P)^2^+0.1600P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0905
_refine_ls_wR_factor_obs         .0857
_reflns_number_observed          7250
_reflns_number_total             7988
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            ab1443.cif
_cod_data_source_block           lax2
_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:

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

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0365P)^2^+0.1600P] 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^)+(0.0365P)^2^+0.1600P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               2006172
_cod_database_fobs_code          2006172