Gaussian and Surface Reactions - Doable? Independent from my general kinetics question here - Estimating Surface Reactions - Liquid, Turbulent Flow - I am only interested in responses regarding Gaussian in this question.

I would like to know if it is feasible to predict or model the influence of a surface (metal) on a reaction between two hydrocarbons (aromatic and aldehyde for example) in Gaussian.
If yes, how would I go about it? (Building a small metal grid and working with it is very computationally intensive - it is the only approach I can think off...) 

(I have access to Gaussian at my university - however I do not have access to Linda, so no shared nodes.)
You did go to Gaussian's Documentation on the subject, right?

In principle, it should work.  In practice, you should consider using massive firepower, and the plane-wave codes (NWChem, abinit, VASP, etc. etc.) 

Also, I question whether any of these codes properly model bond breaking on a surface, i.e.  metal-catalyzed reactions.  Big simulations don't guarantee correct wave functions.

I should point out that surface reactions with plane waves are also difficult. At least they used to be.  There are/were issues with Ewald summation having to be done in 3D, and so the surface normal dimension used to have to be HUGE to avoid image effects.

This is a tough business.