Hello Maria

Please take some time to read the following review:

J. Tomasi, B. Mennucci, and R. Cammi, “Quantum mechanical continuum solvation models,” Chem. Rev., 105 (2005) 2999-3093. DOI: 10.1021/cr9904009

It will help answer some your queries related to solvation in QM calculations

Pansy

Thanks a lot Pansy!

if do you mean mathematical model, this must be from parameters causes this solvent in light Gaussian distribution