[ghemical-devel] Tripos Parameters

[Tommi Hassinen]

On Sat, 5 Aug 2006, Geoffrey Hutchison wrote:
> On Aug 5, 2006, at 12:01 PM, Donald Ephraim Curtis wrote:
>
>> Is there anyone here who happens to have a license with Tripos that could 
>> call support and get the extended Tripos parameters.
>
> I don't think that's likely. If parameterization is published, then it's 
> public knowledge. But in the case of unpublished data, it's copyright by the 
> author (i.e., Tripos).

I agree.

> If you want a Tripos-like force field, I can think of two alternatives:
> * Changing the Ghemical code to substitute elements in the same group and use 
> a different atomic radius / bond length. (Not great, but easy to do.)
> * Reverse-engineering the parameters by evaluating the energy and geometry 
> optimization of a range of Si compounds using Tripos.
>
>> I have been contacted by a colleague who would like to get the Si and other 
>> force fields into ghemical but the paper where the original parameters came 
>> from doesn't include those fields.
>
> As we discussed on the list before, there are a range of other, more modern 
> force fields. UFF and MMFF94 come to mind. The latter even has a public test

I have started the work on UFF, and I have now typed the parameter tables 
in ; soon I can start the actual coding. Let's see what I can do...

Regards,

 	Tommi