From charlesreid1

More information on Cantera's diffusion models here: Cantera/Diffusion

Multicomponent diffusivities:

$ D_{kj} $

Mixture averaged diffusivities:

$ D_{km} = \dfrac{1-Y_k}{ \sum_{j \neq k}^{K} \dfrac{ X_j }{ \mathbb{D}_{jk} } } $

Binary diffusivities:

$ \mathbb{D}_{jk} $