Dear all,
I have constructed a solid-liquid interface model with water as the liquid phase. During the AIMD simulation, I used the NPT ensemble. However, I noticed that under the NPT ensemble, the entire model's lattice changes significantly, especially the volume of the water in the upper liquid phase, which leads to an inconsistent density. I would like to know if there is a way to maintain a constant density of 1 g/cm3 for the water box while using the NPT ensemble？
Hope you can help me.
How to maintain constant density of water with NPT ensemble?
Moderators: Global Moderator, Moderator
-
jun_yin2
- Newbie
- Posts: 25
- Joined: Wed Jul 20, 2022 7:18 am
-
marie-therese.huebsch
- Full Member
- Posts: 211
- Joined: Tue Jan 19, 2021 12:01 am
Re: How to maintain constant density of water with NPT ensemble?
Hi,
In principle, it is not surprising the volume changes in an NpT ensemble. Can you specify what you mean by inconsistent density? Often it is hard to find a suitable value for LANGEVIN_GAMMA_L and PMASS. If they are too large, the simulation time becomes very long; if they are too small, the system can blow up (meaning that there are large fluctuations in pressure and volume).
To help further, I would need to see the input and main output as described in the forum guidelines.
Marie-Therese
In principle, it is not surprising the volume changes in an NpT ensemble. Can you specify what you mean by inconsistent density? Often it is hard to find a suitable value for LANGEVIN_GAMMA_L and PMASS. If they are too large, the simulation time becomes very long; if they are too small, the system can blow up (meaning that there are large fluctuations in pressure and volume).
To help further, I would need to see the input and main output as described in the forum guidelines.
Marie-Therese