Re: [lammps-users] Free energy calculation FEP 10-01 / FDTI 10-01

Several examples are provided with LAMMPS of this kind of calculation.
The two routes \lambda 0 → 1 and 1 → 0 should give similar results in absolute value, as you can see in the examples.
Maybe you have a mistake somewhere.
It could help to decouple the activation/deactivation of the LJ terms (adapting lambda on the pair/soft only) and of the charges (with the LJ atoms fully present). The fep commands will be simpler and you can isolate the cause of inconsistency.
Always keep the system charge neutral.

Agilio Padua