volume expansion

Hi all

I am studying about lipid aggregation in water box.

I used minimize and NPT command to relax system and fix density.

And then NVT ensemble was used for trajectory.

But box volume was expanded then distances between molecules were wided.

(volume expansion can be checked using logfile)

There was also strange phenomena.

There was fluctuating of simulation box like heart beat after expanding.

So I think I got wrong result.

Is it correct or wrong?

If it is wrong, how can I fix it?

Best Regards.

If you turned off the NPT fix after getting to
the density you want, then ran NVT, the box
volume should not change. If it did, then
something is wrong with your script.