How to use the peridynamics module and molecular dynamics in LAMMPS for multiscale coupling

I want to use peridynamics and molecular dynamics in lammps to realize the scratching process of single crystal materials, and observe their crack propagation.As a newbie, I don’t have any idea of how to implement it.Do I need to modify the source code of lammps to implement it?

So you first need to find a tutor to teach you the necessary basics. Then you need to decide on which specific model to implement for your material and what the suitable parameters are. In some cases, you can find them in the published literature, sometimes you can derive them from other studies or experiments. The details depend on the specific Peridynamics model. Only in the case that you want to use a Peridynamics model that is not yet supported by LAMMPS will you need to do programming and adding/modifying source code.