Under the assumption of
and
quantities on the segments 1 and 2,
respectively, (4.7) and (4.8) represent a linear
equation system for the partial current densities of all involved
quantities crossing the interface in normal direction. In these equations
All coefficients ,
,
,
and
are functions of the simulation time
,
the process temperature
,
and
the spatial coordinates
and
.
The coefficients
and
may depend on the concentrations of the quantities on both sides of the
interface. The model developer has to provide MDL classes which
determine the actual values of the coefficients and their derivatives to
the quantity concentrations which are the dependent variables in the
PROMIS-NT internal equation system.