Useful SMARTS
Rotatable bonds [!$(*#*)&!D1]-&!@[!$(*#*)&!D1]
Secondary amides [N&H1&D2]-&!@[#6&X3]
H-acceptors [$([!#6;+0]);!$([F,Cl,Br,I]);!$([o,s,nX3]);!$([Nv5,Pv5,Sv4,Sv6])]
Isolating carbons [#6;!$(C(F)(F)F);!$(c(:[!c]):[!c]);!$([#6]=,#[!#6]);!$([#6;!+0])]
Stereo atoms [$([X4&!v6&!v5;H0,H1]),$([SX3]([#6])([#6])~O)]
Stereo bonds [CX3;!H2]=[CX3;!H2]
Stereo allenes [CX3;H0]=C=[CX3;H0,H1]