About interparticle forces between pair of particles

[yewalenikhil65]

DiffEqJump now has spatial SSAs. Thats awesome.

I was wondering whether modeling interparticle forces between pair of molecules is important in this area of jump processes on spatial grids. (Not very familiar with reactions on spatial grids, but such methods are used in fluid simulations)

For example using fixed-radius point neighbor algorithms or nearest neighbor algorithms?? (It's something I can contribute on)

[isaacsas]

Sorry for missing this post! Yes, people definitely are interested in systems with interparticle forces. We've actually worked out a method recently to handle them in reaction-drift-diffusion situations and are currently running some validation tests on it. Hopefully longer-term we can get such functionality into DiffEqJump. I'm not aware of that much on this in the current literature (timestep-based approaches seem more popular for people simulating systems of particles with interparticle forces, which use SDE solvers usually).

[yewalenikhil65]

sometime back i came across paper A hybrid smoothed dissipative particle dynamics (SDPD) spatial stochastic simulation algorithm (sSSA) for advection–diffusion–reaction problems

I think this can be set as future enhancement goal ? I have some experience with SPH/SDPD based methods for fluid flow, but not much with spatial SSAs yet

[isaacsas]

I think that would need to be its own package. SDPD simulations are much more molecular-dynamics in how they work, with all the optimizations that typically are used there. The particle reaction-diffusion part is event-driven, but just a small component (it might be doable with the spatial tooling we have added / are adding).

[isaacsas]

You'll notice that they use the LAMPS MD package for much of the functionality in that paper...

[ChrisRackauckas]

Yeah, the plan for this kind of stuff would be to mix in NBodySimulator.jl. But that would be a whole separate repo.

[yewalenikhil65]

I think let this issue remain open. We can transfer the issue later to appropriate place. When I get some time, I would like to add some SPH based code n some ideas on how to add currently available spatial jump code.