Finding a reaction pathway thanks to Gaussian calculations is tricky exercise requiring a lot of resources for each step of this time-consuming process. Thus, man needs to wonder if each calculation has to be performed or not in order to gain as much time and resource as possible.
After achieving a 3-step mechanistic path for my reaction in gas, meaning finding all optimized structures, TS, verifications by frequencies of the stationary points and IRC, I now need to use the PCM model in my calculations to provide a solvent correction to my mechanism. However, I was wondering which calculations were required for this purpose.
From the 2 options I have in front of me, which is more consistent to avoid wasting time and resources ?
- Perform new optimizations for the minima and TS in my pathway using the PCM model. Then calculate frequencies to be sure of my stationary points.
- Perform new optimizations of the minima and TS AND perform new IRC calculations from the fresh new TS (after solvent correction) with PCM model.
The first option means that I perform an optimization from the reverse and forward structures (already further optimized) obtained from my IRC calculation in gas. The second option means that I calculate a new IRC to obtain new forward and reverse structures that I have to optimize again.