diff --git a/runs/ALPHIE_Grid/README.txt b/runs/ALPHIE_Grid/README.txt
new file mode 100644
index 0000000..d2711d8
--- /dev/null
+++ b/runs/ALPHIE_Grid/README.txt
@@ -0,0 +1,7 @@
+Alphie grid system.
+
+The file mesh.geo can be easily modified to generate new grids to test different configurations.
+
+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.