Hi Lammps Users,
I am working on freezing the impure water and making ice. I need to calculate radial distribution function and free energy during the process.
I know that I can use rdf command to calculate radial distribution function. But I am not understanding how to use that command.
Also, I have read some instructions about fix command to calculate free energy. There are some guidelines to do with umbrella sampling using Alan’s WHAM. How to approach that?
Is there any easier way to get these done? Or, how should I approach this to make it less complicated?
Can anyone please help? Me and my professor both knew to this, we have no idea how to proceed next.
Thank you.
My advice: study the literature (and not just google around) and find a collaborator that has some experience with both, the simulation software and computing properties. Worrying about how to realize the details with the simulation software is a minor problem in that regard and can be figured out later with rather little effort.
For example, getting a box of water molecules to freeze spontaneously is not so straightforward, since freezing is an activated process. You can have supercooled water way below the freezing point when there is no nucleation. That even works on the macroscopic level! It is a simple experiment where you put a plastic(!!) bottle with water into the freezer and it will remain liquid until you shake or otherwise disturb it.