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Table 1 Standardization rejection rates

From: PubChem chemical structure standardization

  Organic Inorganic Mixed Total
Number of substances 102,428,688 53,097 2,188,004 104,669,789
Verify element 107 14 20 141
Verify hydrogens
Verify functional groups
Verify valence 242,615 836 122,034 365,485
Standardize annotations  
Standardize valence bond 8245 165 1833 10,243
Standardize aromaticity  
Standardize stereochemistry  
Standardize explicit hydrogens 458 28 486
Rejected substances 251,425 1015 123,915 376,355
Rejection rate 0.25% 1.91% 5.66% 0.36%
Successfully standardized substances 102,177,263 52,082 2,064,089 104,293,434
Success rate 99.75% 98.09% 94.34% 99.64%
  1. Listed in the table is the absolute number of rejected substances for every step of the PubChem standardization protocol and the total as well as the overall standardization rejection rate for every structure class (organic, inorganic, mixed) as applied to the PubChem Substance database