[gmx-users] Normal to see volume expansion

[Jun Qian]

Hello:

When I put a simple cube box of SPC water molecules and have 4.5v/nm
electric field. I see volume expand hugely, and pressure goes from negative
to positive to negative to ... all the simulation time.

My question is how they adjust volume and pressure at the same time in
Gromacs. It seems Pressure and Volume are relative by Pressure * Volume
equal something...

Thank you in advance!

Jun