Alchemical Free Energy calculation (dH/d\lambda) of a tabulated potential

GROMACS version: 2018.8
GROMACS modification: No

I am using tabulated potentials simulation to model lanthanides non-bonded interactions (12-6-4) form instead of standard (12-6) form.

I am now trying to calculate the solvation free energy of those lanthanides through fading them in or out of the solution using alchemical path.

However, I am not sure if gromacs handles non-standard tabulated potential energy function derivative with respect to lambda (dh/dl) correctly or not.

I’ve looked into the manual, and there was nothing about how dh/dl is calculated for tabulated non-bonded interactions (like vdw and coulomb).

My question would be, does gromacs know how to handle derivates with respect to lambda of tabulated non bonded potentials ?

If not, is there a way to compute solvation free energy in gromacs of those lanthanides described through those non-bonded tabulated potentials ?

Thank you,
Hossam