Rotational Kinetic Energy after Electric field

GROMACS version: 2020.4
GROMACS modification: No

Hello all!

I have been using GROMACS to simulate monophasic and biphasic systems including water and cyclohexane and the application of an external electric field allowed by the software.

In an attempt to analyze the rotational kinetic energy from the command gmx traj, I did not observe any change with or without the electric field which is not expected for the water system. Is there any option I need to consider to properly analyze the expected rotation on the water dipole?

Thank you for your support.

All the best.