[ghemical-devel] Si Parameters for Ghemical 2.02

[Tommi Hassinen]

Hello,

the Si parameters do not exist at all at Tripos 5.2 force field, and 
therefore some default (Hydrogen) parameters have been used in your 
calculation. The elements that have (some) parameters in Tripos 5.2 are : 
H, C, N, O, F, P, S, Cl, Br, I.

Please note that there is no error message (altought there definitely 
should be) when MM some parameters are missing ; instead the atom(s) 
with missing parameters will be selected (which makes them appear purple 
at the graphics screen) and some default parameters are used to make it 
possible to run the calculation.

I will add an warning message to be displayed when some MM parameters are 
missing ; I have simply forgot to add one, because I mostly have tested 
the program with simple organic molecules.

Regards,

 	Tommi


On Mon, 17 Jul 2006, Rzepa, Henry wrote:

> I note that  Silicon in the  (apparent) Tripos 5.2 force field gives odd results.
> For tetramethylsilane for example, one gets a strain energy of  393
> and a C-Si bond length of  1.2A.
>
> Is it possible to check that  a corruption of the Si parameters has
> not occurred?
> -- 
>
> Henry Rzepa.
> +44 (020) 7594 5774 (Voice); +44 (0870) 132 3747 (eFax); rzepahs at mac.com (iChat)
> http://www.ch.ic.ac.uk/rzepa/ Dept. Chemistry, Imperial College London, SW7  2AZ, UK.