After studying LAMMPS for a while, I am eager to conduct a simulation on my own. However, I have encountered some questions and would greatly appreciate your guidance.
**Research Objective:**I aim to investigate the delamination of 3D MXene into 2D MXene during a shaking process. In this scenario, water molecules flush the surface of 3D MXene, leading to the detachment of 2D MXene. Additionally, due to stress concentration at the interface between 2D and 3D MXene, there is a possibility of 2D MXene fracturing during the delamination process.
1.Defining Delamination Force: In studies like Lorenzo Botto’s "Viscous peeling of a nanosheet,"https://pubs.rsc.org/en/content/articlelanding/2022/sm/d1sm01743h the delamination of graphene was modeled by directly applying an upward tensile force. Should I adopt a similar approach for my simulations, or is there a more suitable method to define the delamination force in this context? 2.Force Field Selection: For this process, should I use the ReaxFF force field alone, or is it advisable to combine ReaxFF with the TIP4P water model? 3.Ion Inclusion for Charge Balance: To maintain charge neutrality in the system, I plan to introduce ions. Should I consider the interactions between these ions and the water molecules, as well as between the ions and the 2D MXene? Are these interactions significant and necessary to include in the simulations?
Long story short, this is a significantly non-trivial project you are proposing that involves several competing scientific factors:
As you have noted yourself, a reactive force field (like ReaxFF) is necessary to model bond breaking and possible fracture of MXene. But you would have to find a specific ReaxFF parameterisation that is valid for MXenes. I do not know off the top of my head what water models would be compatible with such a ReaxFF model, but you would have to assume they are not compatible until proven otherwise, especially since most water models are parameterised for long-ranged electrostatics while ReaxFF has short-range electrostatics.
What time and length scales would you need to properly simulate delamination?? A MXene flake is both large and stuff, whereas graphene can be expected to bend (good job looking up prior literature).
How would you know what the local ionic concentrations should be? (Which is the least of your concerns but non-trivial – there is no telling if the ions are more concentrated near the MXene due to its different relative electrical conductivity.)
We have a tradition in the LAMMPS forum of asking users to move their threads to Science Talk if they are primarily science-based, and to keep discussions in the LAMMPS forum only if they concern unexplainable behaviours of LAMMPS itself. This thread is an example of that – I happen to work in 2D materials so I can highlight these concerns but most LAMMPS forum regulars may not have the same experience level. Regardless, you should definitely try a smaller, more manageable problem first.