# How to apply solvent-correction to Gaussian derived Gibbs energies?

I study reaction A + B → C + D in a water using DFT. I think I should apply some kind of correction over RRHO because it is not true in a solvent. I found the given work (https://doi.org/10.1021/jp980229p) and got to the point of calculating that p=1358 atmospheres... How could I now apply it for Gibbs free energies / reaction barriers? Best

• The answers on mattermodeling.stackexchange.com/questions/10249/… can help? Feb 21 at 10:52
• This leads to the computations on solvation free energy. I seek on how to apply correction to translational entropy for the solvated systems already. Gaussian, by default, assume 1 atmosphere pressure what is nonsense for a liquid such as water which as it actually 1358 times greater... Feb 21 at 11:59

I'll reproduce the two equations needed here: $$q_{trans}=(2\pi Rm/h^2)^{3/2}(RT/P)$$ Note that the above is the same as equation 16 in the Martin paper linked. $$S_{trans}=R(lnq_{trans}+3/2)$$