NPT-confined water

Dear LAMMPS users ,

I have a question about using NPT for water confined between graphene layers .

Actually I can’t understand How they use NPT for these systems because with NPT system’s pressure goes well but I think there is no control on water molecules confined between graphene layers !

for example in this paper they have used NPT with high pressure : http://journals.aps.org/prb/pdf/10.1103/PhysRevB.92.245428

I will be grateful if you can let me know how they can preserve water between graphene layers ?!

​Best Regards ,
Saeed.​

Dear LAMMPS users ,

I have a question about using NPT for water confined between graphene layers
.

Actually I can't understand How they use NPT for these systems because with
NPT system's pressure goes well but I think there is no control on water
molecules confined between graphene layers !

what do you mean by "no control on water molecules"?

for example in this paper they have used NPT with high pressure :
http://journals.aps.org/prb/pdf/10.1103/PhysRevB.92.245428

I will be grateful if you can let me know how they can preserve water
between graphene layers ?!

isn't that a question, you should ask the authors of that paper?
if you ask them, i suggest you also explain what you mean by "preserve".

axel.

Dear Axel ,
Thanks for your reply .
i used two graphene layers and water molecules confined between them , and I tried " NPT anisio " and also " NPT x and y " and I used high pressure ( ~2GPa )
System’s pressure goes well but water molecules don’t stay between graphene layers and they come out !
I sent an Email to them but they did not answer !
Regards,

Saeed.

Dear Axel ,
Thanks for your reply .
i used two graphene layers and water molecules confined between them , and I
tried " NPT anisio " and also " NPT x and y " and I used high pressure (
~2GPa )
System's pressure goes well but water molecules don't stay between graphene
layers and they come out !

LAMMPS does (very literally) what you tell it to do. if it doesn't do
what you expect, perhaps you haven't told LAMMPS correctly.

I sent an Email to them but they did not answer !

but it is not the job of the lammps-users mailing list to fill in for
people that don't answer questions about their research. the same goes
if you have trouble realizing your research project. that should be
primarily the concern of your adviser. if people on this list
volunteer advice then all the better, but what you are asking about
is primarily about how to realize your research and not how LAMMPS
works.

axel.

I don’t understand why you continue to struggle with NPT. Why not use NVT or NVE. The physics is the same, up to fluctuations of order O(1/N).

Dear Aidan ,

Actually I have changed it to NVT and this was a general question about using NPT for these kinds of systems .

I just wanted to know how they can do that .
Thanks for your attention
Best Regards ,
Saeed.