(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2005). E61, o2674-o2676 [ doi:10.1107/S1600536805022877 ]

Bis(nicotinic acid) hydrogen perchlorate

S. Athimoolam and R. K. Rajaram

Online 23 July 2005

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.004 Å
R factor = 0.043
wR factor = 0.127
Data-to-parameter ratio = 9.9

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT355_ALERT_3_A Long    O-H Bond (0.82A)   O1B    -   H1B    ...       1.23 Ang.

Author Response: The H atom lies on the inversion center and links the two nicotinic

 acid residue through strong symmetric O-H...O hydrogen bond.


Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.96       
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       9.93       
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K     
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K     
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.04       
PLAT751_ALERT_4_C Bond    Calc     1.23000, Rep  1.2320(18) ......  Senseless su    
              O1B  -H1B     1.555   1.555                                       
PLAT752_ALERT_4_C Angle   Calc      112.00, Rep  112.11(18) ......  Senseless su    
              C31  -O1B  -H1B     1.555   1.555   1.555                         

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

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