Void ratio of the micropores.
It can be calculated as e_{\text{m}} = \frac{V_{\text{m}}}{V_{\text{s}}_{\text{m}}}Double subscripts: use braces to clarify, where V_{\text{m}} is the volume of the micropores, and V_{\text{s}} is the solid volume.
No additional info.
Used in no end-to-end test cases.
