Re: [cclib-devel] contribute to cclib

[Noel O'B. <noe...@ma...>]

On Tue, 2006-08-29 at 16:21 +0200, Mehdi Bounouar wrote:
> > So you're saying that it's possible to calculate the cartesian
> > displacements from the FCM. How is this done exactly? It's possible that
> > we will extract both, as many output files will only contain the
> > cartesian displacements. However, we will provide (separately) a method
> > to calculate the cartesians from the FCM, if this is possible.

> I have put an attachment that shows how to do this,
> the principle should be correct as the values are close, 
> Note: the cartesian displacements vectors are sometimes of opposite signs.

Thanks for the code. I'll make it into a function and add it to the
algorithms when I get a chance. The opposite signs are an artefact or
are they significant? For visualisation I would say it's not important;
but might this be significant for other uses? Is there some convention
on these things that we should be obeying, e.g. something in that book
by Decius, Cross and Wilson that is covered with dust on my bookshelf?

> > Are you familiar with so-called scaled
> > quantum mechanical (SQM) methods? e.g.
> > http://dx.doi.org/10.1016/j.theochem.2006.03.025
> > It would be nice to extract the information necessary for such a study,
> > and then to implement the method as an algorithm. I remember trying to
> > do this during my PhD but I didn't have access to any software to do
> > this, nor did I have the technical background to be able to do this
> > myself. If the FCM were required for this, I think it would certainly
> > justify extracting it. Do you know what else is needed?
> 
> Honestly, I have no idea :-) but I will try to have a look it.

It's no big deal - I guess we should concentrate on the parser first.
However, it might be interesting as there is no free software available
to do this kind of thing.

BTW, once Adam gets back from holidays we can sort out making you a
developer. Unfortunately, I'm going on holidays for a week this Friday
as well as changing postdocs. But I'd like to get you up and running as
soon as possible, so stay tuned.


> Mehdi