Hille equation

The Hille equation relates the maximum ionic conductance of an ion channel to its length and radius (or diameter), with the commonly used version implicitly takes into account a hemispherical cap. As it is ultimately based on a macroscopic continuum model, it does not take into account molecular interactions, and real conductances are often several times less than the predicted maximal flux.
Equation.
The Hille equation predicts the following maximum conductance formula_1 for a pore with length formula_2, radius formula_3, in a solvent with resistivity formula_4:
formula_5
Rearranging the terms, the maximal flux based on length formula_2 and diameter formula_7 can be shown to be:
formula_8