[gmx-users] how to manipulate solute-solvent interactions in ff to get the correct solvation free energy?

[Golshan Hejazi]

Dear all,

I have computed the solvation free energy of a molecule in a non aqueous solvent using thermodynamics integration in gromacs. The value is negative and high (-70kj/mol). The experimental value is almost -52kj/mol. 

From the output of TI, there exist a lambda value which correspond to ~-53kj/mol and I would like to manipulate the force field parameters for the interaction between molecule and solute in order to get the right solvation free energy! 

Is it possible to do it in gromacs?
Any comment or reference is highly appreciated

Best
G.