Geometry optimization

I optimized a dimer (file attached psi.dat). And after the optimization, I increased the distance between the dimer and calculated the energy of each configuration and created a trajectory ( When plotted, second configuration seems to have lower energy than the optimized geometry. Please see. Thanks in advance. (25.6 KB)
psi.dat (2.1 MB)

  1. What is the unit of the y-axis/energy in this plot?
  2. Have you tried optimizing with tighter convergence thresholds? It might clarify the issue one way or the other to do that.

I see you used “g_convergence qchem”. This criterion allows convergence for small forces (and energy changes) even with large displacements so that’s probably the cause of the inconsistency.

The energy in y axis is in Eh.