Hi,
> Would like some help on writing SMARTS:
> I would like a SMART for urea currently I have the following :
> [NX3][NX3][CX3]=[OX1]
> but this does not seem to be able to find urea in a
> structure.
That's right, this smarts represents carboxyhydrazine (NNC=O) :)
> Any help on witting SMARTS
I've looked into the stereo examples and fixed 1 and 2 in SVN,
bringing the number of failures down to 554.
Number 6 was by design, but I've queried whether this is the right
thing to do on the Blue Oblelisk exchange
(http://blueobelisk.shapado.com/questions/how-should-unspecified-tetrahedral-ster
