FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Sulfur Phosphorus Phosphine (F610000) Phosphino (F616000) Phosphonate (F620000) Phosphite (F630000) Phosphate ester (F640000) Phosphorothioate (F660200) Thiophosphate (F660200) Amino phosphate (F661100) Halogen Boron Magnesium Silicon Iron Cobalt Asenic Selenium Tin