LAMMPS SPC/E Water: Energy vs volume data

Hello,
I have with running MD simulations of SPC/E Water using LAMMPS. I have run several MD simulations using the script (http://lammps.sandia.gov/bench/in.spce.txt) with constant N,vol, temp to calculate the energies as a function of vol/density and find the density that gives me a minimum in total energy. In addition, I have run NPT runs to calculate the same.

I was expecting a minimum in energy at the equilibrium volume. However, the energy of the system is observed to decrease continuously with volume/density even after the pressure transitions from tensile to compressive.

Has anyone seen anything similar? or am I doing anything wrong? An example logfile for a nve run is also given below. Your help and suggestions are greatly appreciated. I look forward to your reply.

A. D.
My vol-energy-pressure data is as follows:

I suggest you try using the current LAMMPS. There
may have been a bug fix that affects your results
in the last 1.5 years.

Steve

I suggest you try using the current LAMMPS. There
may have been a bug fix that affects your results
in the last 1.5 years.

perhaps, it may also be useful to make the
convergence for both pppm and shake tighter.

axel.

Dear Steve,
Thanks for the suggestion. I will get the newest release right away.