more than two ester groups 	C(=O)O[C,H1].C(=O)O[C,H1].C(=O)O[C,H1]
2-halo pyridine 	n1c([F,Cl,Br,I])cccc1
acid halide 	C(=O)[Cl,Br,I,F]
acyclic C=C-O 	C=[C!r]O
acyl cyanide 	N#CC(=O)
acyl hydrazine 	C(=O)N[NH2]
aldehyde 	[CH1](=O)
Aliphatic long chain	[R0;D2][R0;D2][R0;D2][R0;D2]
alkyl halide 	[CX4][Cl,Br,I]
amidotetrazole 	c1nnnn1C=O
aniline 	c1cc([NH2])ccc1
azepane 	[CH2R2]1N[CH2R2][CH2R2][CH2R2][CH2R2][CH2R2]1
Azido group 	N=[N+]=[N-]
Azo group 	N#N
azocane 	[CH2R2]1N[CH2R2][CH2R2][CH2R2][CH2R2][CH2R2][CH2R2]1
benzidine 	[cR2]1[cR2][cR2]([Nv3X3,Nv4X4])[cR2][cR2][cR2]1[cR2]2[cR2][cR2][cR2]([Nv3X3,Nv4X4])[cR2][cR2]2
beta-keto/anhydride 	[C,c](=O)[CX4,CR0X3,O][C,c](=O)
biotin analogue 	C12C(NC(N1)=O)CSC2
Carbo cation/anion 	[C+,c+,C-,c-]
catechol 	c1c([OH])c([OH,NH2,NH])ccc1
charged oxygen or sulfur atoms	[O+,o+,S+,s+]
chinone 	C1(=[O,N])C=CC(=[O,N])C=C1
chinone 	C1(=[O,N])C(=[O,N])C=CC=C1
conjugated nitrile group 	C=[C!r]C#N
crown ether 	[OR2,NR2]@[CR2]@[CR2]@[OR2,NR2]@[CR2]@[CR2]@[OR2,NR2]
cumarine 	c1ccc2c(c1)ccc(=O)o2
cyanamide 	N[CH2]C#N
cyanate / aminonitrile / thiocyanate 	[N,O,S]C#N
cyanohydrins 	N#CC[OH]
cycloheptane 	[CR2]1[CR2][CR2][CR2][CR2][CR2][CR2]1
cycloheptane 	[CR2]1[CR2][CR2]cc[CR2][CR2]1
cyclooctane 	[CR2]1[CR2][CR2][CR2][CR2][CR2][CR2][CR2]1
cyclooctane 	[CR2]1[CR2][CR2]cc[CR2][CR2][CR2]1
diaminobenzene 	[cR2]1[cR2]c([N+0X3R0,nX3R0])c([N+0X3R0,nX3R0])[cR2][cR2]1
diaminobenzene 	[cR2]1[cR2]c([N+0X3R0,nX3R0])[cR2]c([N+0X3R0,nX3R0])[cR2]1
diaminobenzene 	[cR2]1[cR2]c([N+0X3R0,nX3R0])[cR2][cR2]c1([N+0X3R0,nX3R0])
diazo group 	[N!R]=[N!R]
diketo group 	[C,c](=O)[C,c](=O)
disulphide 	SS
enamine 	[CX2R0][NX3R0]
ester of HOBT 	C(=O)Onnn
four member lactones 	C1(=O)OCC1
halogenated ring	c1cc([Cl,Br,I,F])cc([Cl,Br,I,F])c1[Cl,Br,I,F]
halogenated ring 	c1ccc([Cl,Br,I,F])c([Cl,Br,I,F])c1[Cl,Br,I,F]
heavy metal 	[Hg,Fe,As,Sb,Zn,Se,se,Te,B,Si]
het-C-het not in ring 	[NX3R0,NX4R0,OR0,SX2R0][CX4][NX3R0,NX4R0,OR0,SX2R0]
hydantoin 	C1NC(=O)NC(=O)1
hydrazine 	N[NH2]
hydroquinone 	[OH]c1ccc([OH,NH2,NH])cc1
hydroxamic acid 	C(=O)N[OH]
imine 	C=[N!R]
imine 	N=[CR0][N,n,O,S]
iodine 	I
isocyanate 	N=C=O
isolated alkene 	[$([CH2]),$([CH][CX4]),$(C([CX4])[CX4])]=[$([CH2]),$([CH][CX4]),$(C([CX4])[CX4])]
ketene	C=C=O
methylidene-1,3-dithiole 	S1C=CSC1=S
Michael acceptor	C=!@CC=[O,S]
Michael acceptor 	[$([CH]),$(CC)]#CC(=O)[C,c]
Michael acceptor 	[$([CH]),$(CC)]#CS(=O)(=O)[C,c]
Michael acceptor 	C=C(C=O)C=O
Michael acceptor 	[$([CH]),$(CC)]#CC(=O)O[C,c]
N oxide 	[NX2,nX3][OX1]
N-acyl-2-amino-5-mercapto-1,3,4-thiadiazole 	s1c(S)nnc1NC=O
N-C-halo 	NC[F,Cl,Br,I]
N-halo 	[NX3,NX4][F,Cl,Br,I]
N-hydroxyl pyridine 	n[OH]
nitro group 	[N+](=O)[O-]
N-nitroso 	[#7]-N=O
oxime 	[C,c]=N[OH]
oxime 	[C,c]=NOC=O
Oxygen-nitrogen single bond 	[OR0,NR0][OR0,NR0]
perfluorinated chain 	[CX4](F)(F)[CX4](F)F
peroxide 	OO
phenol ester 	c1ccccc1OC(=O)[#6]
phenyl carbonate 	c1ccccc1OC(=O)O
phosphor 	P
phthalimide 	[cR,CR]~C(=O)NC(=O)~[cR,CR]
Polycyclic aromatic hydrocarbon 	a1aa2a3a(a1)A=AA=A3=AA=A2
Polycyclic aromatic hydrocarbon 	a21aa3a(aa1aaaa2)aaaa3
Polycyclic aromatic hydrocarbon 	a31a(a2a(aa1)aaaa2)aaaa3
polyene 	[CR0]=[CR0][CR0]=[CR0]
quaternary nitrogen 	[s,S,c,C,n,N,o,O]~[nX3+,NX3+](~[s,S,c,C,n,N])~[s,S,c,C,n,N]
quaternary nitrogen 	[s,S,c,C,n,N,o,O]~[n+,N+](~[s,S,c,C,n,N,o,O])(~[s,S,c,C,n,N,o,O])~[s,S,c,C,n,N,o,O]
quaternary nitrogen 	[*]=[N+]=[*]
saponine derivative 	O1CCCCC1OC2CCC3CCCCC3C2
silicon halogen 	[Si][F,Cl,Br,I]
stilbene 	c1ccccc1C=Cc2ccccc2
sulfinic acid 	[SX3](=O)[O-,OH]
Sulfonic acid 	[C,c]S(=O)(=O)O[C,c]
Sulfonic acid 	S(=O)(=O)[O-,OH]
sulfonyl cyanide 	S(=O)(=O)C#N
sulfur oxygen single bond 	[SX2]O
sulphate 	OS(=O)(=O)[O-]
sulphur nitrogen single bond 	[SX2H0][N]
Thiobenzothiazole 	c12ccccc1(SC(S)=N2)
thiobenzothiazole 	c12ccccc1(SC(=S)N2)
Thiocarbonyl group 	[C,c]=S
thioester 	SC=O
thiol 	[S-]
thiol 	[SH]
Three-membered heterocycle 	*1[O,S,N]*1
triflate 	OS(=O)(=O)C(F)(F)F
triphenyl methyl-silyl 	[SiR0,CR0](c1ccccc1)(c2ccccc2)(c3ccccc3)
triple bond 	C#C
