diff --git a/diffusivityModel/Particle/Particle.C b/diffusivityModel/Particle/Particle.C
index 840448d..5362536 100644
--- a/diffusivityModel/Particle/Particle.C
+++ b/diffusivityModel/Particle/Particle.C
@@ -52,9 +52,12 @@ const Foam::scalar Foam::Particle::Angstrom = 1e-10;
 //- 1 Debye in [ Coulomb x meter ]
 const Foam::scalar Foam::Particle::Debye = 1.0 / 2.99792458e29;
 
-//- Boltzmann constant (default in [J/K])
+//- Circumference / Diameter
 const Foam::scalar Foam::Particle::pi = constant::mathematical::pi;
 
+//- Electric constant (Vacuum permittivity) [F/m]
+const Foam::scalar Foam::Particle::eps0 = constant::electromagnetic::epsilon0.value();
+
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
@@ -73,7 +76,7 @@ Foam::Particle::Particle(const dictionary& dict)
     W_(readScalar(dict["W"])),
     z_(readScalar(dict["z"]))
 {
-    label geometry (dict.lookupOrDefault("geometry", 0));
+    label geometry = 0;
 
     const entry* entryPtr = dict.lookupEntryPtr("tranlib", false, true);
 
@@ -82,6 +85,10 @@ Foam::Particle::Particle(const dictionary& dict)
         scalarList tranlib(entryPtr->stream());
         geometry = tranlib[0];
     }
+    else
+    {
+        geometry = readLabel(dict.lookup("geometry"));
+    }
 
     switch(geometry)
     {
diff --git a/diffusivityModel/Particle/Particle.H b/diffusivityModel/Particle/Particle.H
index a378e72..eab0793 100644
--- a/diffusivityModel/Particle/Particle.H
+++ b/diffusivityModel/Particle/Particle.H
@@ -118,12 +118,15 @@ public:
         //- 1 Angstom in meter
         static const scalar Angstrom;
 
-        //- 1 Angstom in meter
+        //- 1 Debye in [ Coulomb x meter ]
         static const scalar Debye;
 
         //- Circumference / Diameter
         static const scalar pi;
 
+        //- Electric constant (Vacuum permittivity) [F/m]
+        static const scalar eps0;
+
 
     // Constructors