The interface and bulk contributions are not
decoupled under equilibrium conditions if the condition
of equal concentrations [23] is adopted, while a
significant simulation complexity is resulted from the
condition of equal diffusion potentials [24–26]. These
two problems can be solved successfully if the
additional constraint equation (7) is solved self-
consistently in thermodynamics by the EF [11–13]
or the TEP [14–16,17].