GENERIC GROUP CATEGORIES USED IN STN CHEMICAL STRUCTURE BUILDING

        
                       Abbreviation     Meaning
        
                            LIN         linear
                            BRA         branched
                            SAT         saturated (all single bonds)
                            UNS         unsaturated (at least one bond
                                         not single)
                            LOC         low carbon (6 or fewer carbons)
                            HIC         high carbon (more than 6 carbons)
                            LOQ         low hetero (only 1 non-carbon
                                         atom)
                            HIQ         high hetero (more than one  non-
                                         carbon atom)
                            MCY         monocyclic
                            PCY         polycyclic