diff --git a/org/qmckl_electron.org b/org/qmckl_electron.org
index f78faf6..b41ac14 100644
--- a/org/qmckl_electron.org
+++ b/org/qmckl_electron.org
@@ -1758,6 +1758,15 @@ assert(fabs(en_distance[1][0][1] - 3.1804527583077356) < 1.e-12);
 
 ** Electron-nucleus rescaled distances
 
+   ~en_distance_rescaled~ stores the matrix of the rescaled distances between 
+   electrons and nucleii.
+
+   \[
+   C_{ij} = \left( 1 - \exp{-\kappa C_{ij}}\right)/\kappa
+   \]
+
+  where \(C_{ij}\) is the matrix of electron-nucleus distances.
+
 *** Get
 
     #+begin_src c :comments org :tangle (eval h_func) :noweb yes
@@ -2047,7 +2056,7 @@ assert(fabs(en_distance_rescaled[1][0][1] - 0.9584331688679852) < 1.e-12);
   gives the Laplacian $\partial x^2 + \partial y^2 + \partial z^2$.
 
 *** Get
-
+    
     #+begin_src c :comments org :tangle (eval h_func) :noweb yes
 qmckl_exit_code qmckl_get_electron_en_distance_rescaled_deriv_e(qmckl_context context, double* distance_rescaled_deriv_e);
     #+end_src