Inquiry about the Interface modeling in Lammps

Dear all,

I want to simulate a layer of MoS2 on the silicon wafer which is grown by the CVD process, but I do not know how to define the interface between these two layers. I created the layers and defined their potentials, I mean one potential for MoS2 and another for Si which both of them are SW style. Now, I want to define their interface. What should I do? Do I need to define a new pair style? If it is yes, how can I find the pair_coeff between the Si and MoS2 molecules?

With regards,

you can use two different pair styles in the same system via using pair_style hybrid. both pair styles can be of the same type.
however, for hybrid to work, you need to find pairwise additive (e.g. lj/cut or morse or similar) potentials to describe the interactions between the two SW subsystems. those you have to find in the published literature. I don’t think that you are the first person trying to simulate that kind of system, so there are likely publications (and if only to tell you the classical models are not sufficient). technically, it should also be possible to create a merged potential file, if you can find some suitable parameters for the missing mixed terms or a suitable mixing rule that can be applied (not sure, if one exists that is suitable for this kind of system, that is outside my area of research experience). either using hybrid or using a mixing rule will incur some degree of error, that would be avoided if a full parameterization for all 3 elements would exist. at any rate, if there is an answer, it will be most likely in the published literature.