diff --git a/runs/ALPHIE_Grid/README.txt b/runs/ALPHIE_Grid/README.txt
index d2711d8..dac7fb6 100644
--- a/runs/ALPHIE_Grid/README.txt
+++ b/runs/ALPHIE_Grid/README.txt
@@ -5,3 +5,4 @@ The file mesh.geo can be easily modified to generate new grids to test different
 Two cases are provided:
   Clasical case in which ions and electrons are input from the ionization chamber.
   Ionization case in which ion-electron pairs are generated due to the influx of electrons using the Ionization boundary condition.
+    To have the electrons produced by this boundary as a different species add "electronSecondary": "eSec" at the definition of the boundary model.