FGROUP by class
Carbon Carbon skeleton Hydrocarbon ring N-heterocyclic O-heterocyclic S-heterocyclic Mixed-heterocyclic Oxygen Nitrogen Sulfur Phosphorus Halogen Boron Magnesium Silicon Silane (F814100) Disilane (F814210) Disilene (F814220) Silyl ether (F814300) Iron Cobalt Asenic Selenium Tin