(IUCr) Crystallography Journals Online checkcif report

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Acta Cryst. (2004). E60, o1476-o1477 [ doi:10.1107/S160053680401863X ]

(R)-Histidinium (2R,3R)-tartrate

M. N. Johnson and N. Feeder

Key indicators

Single-crystal X-ray study
T = 291 K
Mean (C-C) = 0.003 Å
R factor = 0.030
wR factor = 0.076
Data-to-parameter ratio = 7.3

checkCIF/PLATON results

No syntax errors found




Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.802     0.990
            Tmin' and Tmax expected:      0.931     0.986
            RR' =      0.858
            Please check that your absorption correction is appropriate.
STRVA01_ALERT_2_C           Chirality of atom sites is inverted?
           From the CIF: _refine_ls_abs_structure_Flack    1.100
           From the CIF: _refine_ls_abs_structure_Flack_su    1.000
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98       
PLAT032_ALERT_4_C Std Uncertainty in Flack Parameter too High ....       1.00       
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......       1.10       
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.86       
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.25       
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.10       
PLAT432_ALERT_2_C Short Inter X...Y Contact  O5     ..  C3      ..       2.92 Ang.  

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.35
           From the CIF: _reflns_number_total               1407
           Count of symmetry unique reflns         1592
           Completeness (_total/calc)             88.38%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present           no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   9 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion