Re: [cclib-devel] Forces from gaussian job (added feature)

[Hugh Chaffey-M. <hug...@ch...>]

Hi

thanks for the changes to cclib!

> > In a related project I'm currently working on, I have already written
> > code to convert from forces in cartesians to forces in z-matrix, and it
> > numerically differentiates the function Z(C) that returns z-matrix
> > coordinates, Z, in terms of the cartesians, C, and implements the
> > function Z using the python interface to openbabel.
>
> That code would be a good starting point for these helper methods. Would
> you care to share it?

Sure, when it's in better shape I'll send it through.

I've also re-implemented the z-matrix => cartesian conversion (that is needed 
for the above) from OpenBabel in pure Python (Reasons: the openbabel version 
had bugs, didn't emit xyz with sufficient precision to do numerical 
differentiation, it required a lot of code to utilise it from within Python ). 
I can make both of these available if you want.

> > Well if I were to write some code to parse them, would you want to add it
> > to cclib?
>
> Perhaps. To start off with, we could create a branch of cclib that would
> implement just the gradients for VASP, and when we have enough attributes
> parsed compared to other programs, we could include it in the main
> development branch.

Ok. I will be doing some hacking over the coming months and as I have support 
implemented I'll send it through.

Cheers
Hugh