[lammps-users] Epsilon problems in the use of LJ potential

Dear experts,

I am using LAMMPS to complete my requirements, unit is LJ, but there is a problem here, because I am a multi-particle system, my Epsilon has positive and negative values. As is known to all, epsilon is generally negative, but in the command of LAMMPS, it is positive.1. Can epsolon in the pair_coeff command of LAMMPS be negative (i.e. epsilon is actually positive)?2. I have made an attempt. In fact, my temperature and timestep Settings are reasonable, but a large number of atoms are lost.

These are my questions, I also ask the experts to help me to answer my doubts.

Thank you for your attention


Please talk to your adviser/supervisor/tutor. I am certain you are mixing something up.

The epsilon parameter in a Lennard-Jones potential is always positive because it represents the “strength” of the interaction.
Using a negative epsilon would invert the potential and make it attractive where it should be repulsive and thus it can lead to unphysical trajectories (and things like lost atoms).