Mimicking a substrate with LJ

Hello everyone,

I am trying to model the corrugated 2D on a substrate. However, putting a substrate in the simulation box will increase my computational needs, and I do not have enough sources for that. So, can I use LJ potential to mimic the substrate? Has anyone done such a thing before?

Thank you for your help in advance.

Best regards.

Available computational resources should not be the reason for choosing an inferior model and thus tainting the quality of insights that you can achieve (or invalidating them entirely in the worse case). There are HPC clusters and regional or national supercomputers where you can get access to more capable resources for doing your research. Often those do not cause any additional cost, you just need to find them and write a proposal describing your needs for access and a time allocation.

Changing the potential is rarely a good idea. Either the potential you use is applicable for the material or not. However, there is a straightforward way to reduce the cost in such a model: you can avoid calculation of the intra-substrate interactions. For that you need to a) exclude those atoms from time integration and thus immobilize them and b) exclude computing their interactions with the neigh_modify exclude command.

Thank you for your explanation, Axel.