Checker searches for explicit hydrogens.
The following different types of explicit hydrogens can be searched:
Lonely : hydrogen atom without connection (:lonely=true)
Isotopic : hydrogen isotopes (:isotopic=true)
Charged : charged hydrogen atoms (:charged=true)
Radical : hydrogen radicals (:radical=true)
Mapped : mapped hydrogens (:mapped=true)
Wedged : hydrogen connecting with wedged bond (:wedged=true)
H Connected : hydrogen connected to a hydrogen atom (:hconnected=true)
Polymer End Group : hydrogen connected to a SRU S-group (:polymerendgroup=true)
S-group End : hydrogen connected to a Superatom S-group (:sgroupend=true)
S-group : hydrogen which is the only atom in an S-group (:sgroup=true)
Valence Error : hydrogen connected to an atom which has valence error (:valenceerror=true)
Bridgehead : hydrogen connected to a bridgehead atom (:bridgehead=true)
This picture summarizes the applied categorizations:
 
The corresponding fixer offers removing explicit hydrogens and the selected special atoms (removeexplicith).
Example :
| Explicit Hydrogen Checker ( explicith) | Warning: | Fix | 
|---|---|---|
| Remove Explicit Hydrogen ( removeexplicith) | ||
| Detect Explicit Hydrogen |  ex_explh_ch |  ex_explh_f |