Re: [Open Babel] valence vs implicit valence

[Geoff H. <ghu...@ws...>]

Hi Manoj,

Sorry for the delay in replying--I was on vacation last week.

> Is there a function member of the OBAtom class that returns the number
> of bonds an atom of a particular element is *capable* of forming?

> The documentation says that GetValence() returns the number of
> connections made whereas GetImplicitValence() returns the maximum 
> number
> of connections. Doesn't this mean that in the example I have worked
> with, GetValence() shoudl return 3 but GetImplicitValence() should 
> return 4?

The documentation needs to be cleaned up here. GetImplicitValence() 
essentially returns the number of connections expected for an atom of a 
given type. Take a look at the IMPVAL rules in atomtyp.txt.

What you want is

   etab.GetMaxBonds(atom->GetAtomicNum()))

Cheers,
-Geoff