diff --git a/NonLinearEVP/NonLinearEVP_data.geo b/NonLinearEVP/NonLinearEVP_data.geo
index 9d4714f8e2bdae70205bab34fbb03977145def7a..bb477e8541fe6d300ace768d94d27b46a34065e7 100644
--- a/NonLinearEVP/NonLinearEVP_data.geo
+++ b/NonLinearEVP/NonLinearEVP_data.geo
@@ -3,11 +3,11 @@
 ////   _data.geo               ////
 ///////////////////////////////////
 
-nm       = 1.;
-epsilon0 = 8.854187817e-3*nm;
-mu0      = 400.*Pi*nm;
-cel      = 1.0/(Sqrt[epsilon0 * mu0]);
-deg2rad  = Pi/180;
+// nm       = 1.;
+// epsilon0 = 8.854187817e-3*nm;
+// mu0      = 400.*Pi*nm;
+// cel      = 1.0/(Sqrt[epsilon0 * mu0]);
+// deg2rad  = Pi/180;
 
 pp0        = "1Geometry/0";
 pp1        = "2Polarization-Bloch/0";
@@ -26,8 +26,6 @@ colorpp5   = "Ivory";
 
 DefineConstant[ a_lat = {50     , Name StrCat[pp0  , "1grating period d [nm]"]          , Highlight Str[colorpp0]  , Closed close_menu} ];
 
-// normalization factor
-norm = a_lat/(2.*Pi*cel);
 
 DefineConstant[
   d_sq           = {0.806 , Name StrCat[pp0 , "2sq [d]"] , Highlight Str[colorpp0]  , Closed close_menu} , 
@@ -58,7 +56,16 @@ DefineConstant[
   flag_outEigvec = {1     , Name StrCat[pp4, "output eigenvector?"], Choices{0,1}}
 ];
 
-// Normalization
+// Normalized units so that 2*pi*c/a=1
+cel      = a_lat/(2*Pi);
+epsf     = 8.854187817e-3;
+muf      = 400.*Pi;
+nm       = 2*Pi/(a_lat*Sqrt[epsf*muf]);
+epsilon0 = epsf*nm;
+mu0      = muf*nm;
+norm     = a_lat/(2.*Pi*cel);
+
+// Normalize
 d_sq           = d_sq          * a_lat;
 space2pml      = space2pml     * a_lat;
 pmlsize        = pmlsize       * a_lat;