Dear All,

Sorry for the mess I've created. In fact I started to work from the
latest stable version 2.3.1. And then we I got the SVN version in, I
did not check that there was some update in between for the Conformer
Search. Shame on me!
So I got the latest version before my commit (4914), and
merged with my changes, and commited (r4992). 
So the virtual issues are gones, and latest classes
OBMinimizingEnergyConformerScore and  OBMinimizingRMSDConformerScore
are back in business.

Note the in the OBMinimizingEnergyConformerScore, I also added a map
to bookeep steepest descent + energy result. As a example, in a test
run I made, it gave  9029 request  for  681 actual computations.
I also noted that 

   OBMinimizingEnergyConformerScore::Preferred ()
was set to Highest instead of Lowest (since we focus on the lowest
minimized energy score).

In the  OBStericConformerFilter::IsGood method, there was an issue
with the  value of square distance between 2 atoms. It was originally
set as:
> double distanceSquared = sqrt (dx*dx + dy*dy + dz*dz);
And I guess that, in order to save sqrt compuation time, the intention  was
to set it as:
> double distanceSquared = dx*dx + dy*dy + dz*dz;
As it is later compared with squard cutoff.
Moreover the VdW cutoff is applied to all non directly bonded atoms,
so discarding anything, since e.g. 1-3 carbons in an alcane chain will
be below the sum of VdW radii.
For now I fixed it by applying a factor of 0.6, eg.:
>       double vdwCutoff = 0.6 * (etab.GetVdwRad(atom1->GetAtomicNum())
>                                 + etab.GetVdwRad(atom2->GetAtomicNum()));
I guess this could be improved by discarding 1-3 and 1-4 bonded atoms,
and maybe use a factor of 0.85 or 0.9, as in the end distances below
the VdW radii will reflect in the energy.

Hope this will help... in the end.


BenoƮt




--
View this message in context: 
http://forums.openbabel.org/r4990-breaks-things-tp4655401p4655411.html
Sent from the openbabel-devel mailing list archive at Nabble.com.

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
OpenBabel-Devel mailing list
OpenBabel-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/openbabel-devel

Reply via email to