Mixtures Ginzburg-Landau functional

In order to describe the diffusive dynamics of composition fluctuations in binary mixtures one can extend the time-dependent Ginzburg-Landau methods to the free energy functional of the SCF theory. The approach relies on two ingredients a free energy functional that accurately describes the chemical potential of a spatially inhomogeneous composition distribution out of equilibrium and an Onsager coefficient that relates the variation of the chemical potential to the current of the composition. 

The chemical potential difference in the inhomogeneous liquid mixture is the derivative of the Landau-Ginzburg functional, which in this case describes the local Gibbs energy. 

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