Positive potential energy after energy minimization of alcohol-water system

Hi All, I am working on a water-alcohol binary mixture system. For very low mole fractions of water (just a few water molecules) I am finding during energy minimization step: positive value for energy although Fmax (maximum force) is converged. During the equilibration and production runs, I don’t have any issues/Lincs/ warnings or anything unusual. Does this mean due to largely hydrophobic nature of the alcohol I am obtaining a positive potential energy? When I am increasing the mole fraction of water, during energy minimization, the potential energy is becoming increasingly negative. The alcohol parameters were obtained from cgenff webserver and charmm penalties were close to zero, so I suppose parametrization was not an issue.

Positive potential energy means the magnitude of the bonded interactions is greater than that of the nonbonded interactions, suggesting a system that simply has weak intermolecular interactions. This makes sense for a system with lots of EtOH, which have alkyl interactions. Water is dominated by multiple hydrogen bonds per molecule, which are very favorable.

Thank you for your reply Dr. Lemkul. Now I get this. So, basically for largely hydrophobic system it is fair to get positive potential energies during energy minimization if force is converged due to larger contribution from bonded interaction terms compared to Coulomb and LJ terms.