Coupled Diffusion

[casper-camenisch]

Hello,

I would like to simulate a system with coupled diffusion of two diffusion variables. How is this meant to be done? I've had a look at test_2d_depolarization since it (indirectly over electro_physiology) uses the ReactionDiffusion class, but am having trouble reverse engineering it. Is there a more straight forward example that I'm overlooking? Or has someone done this before?
Some guidance would be greatly appreciated!

Update: To be more specific, I have set up two diffusion species but don't know how to change the local diffusivity for the individual species.
In the test case windows_frame_diffusion_D4 the local diffusivity is set by adjusting the "ThermalConductivity" variable of the particles. I would like to set this value for each species individually, if possible.

[YuVirtonomy]

@Xiangyu-Hu