diff --git a/Basis/ERI.ml b/Basis/ERI.ml
index 93a1cb6..a063491 100644
--- a/Basis/ERI.ml
+++ b/Basis/ERI.ml
@@ -30,7 +30,10 @@ let contracted_class_shell_pairs ?schwartz_p ?schwartz_q shell_p shell_q : float
   TwoElectronRR.contracted_class_shell_pairs ~zero_m ?schwartz_p ?schwartz_q shell_p shell_q
 
 
+let cutoff2 = cutoff *. cutoff
+(*
 type n_cls = { n : int ; cls : Z.t array }
+*)
 exception NullIntegral
 
 (** Write all integrals to a file with the <ij|kl> convention *)
@@ -60,6 +63,8 @@ let to_file ~filename basis =
       ) pair_array ) shell_pairs
   in
 
+  let inn = ref 0 and out = ref 0 in
+
   for i=0 to (Array.length basis) - 1 do
     print_int basis.(i).Contracted_shell.indice ; print_newline ();
     for j=0 to i do
@@ -73,7 +78,7 @@ let to_file ~filename basis =
           for l=0 to k do
             let schwartz_q, schwartz_q_max = schwartz.(k).(l) in
             try
-            if schwartz_p_max *. schwartz_q_max < cutoff *. cutoff then
+            if schwartz_p_max *. schwartz_q_max < cutoff2 then
               raise NullIntegral;
             let
               shell_q = shell_pairs.(k).(l)
@@ -103,18 +108,23 @@ let to_file ~filename basis =
                               Zmap.find cls key 
                             in
                             if (abs_float value > cutoff) then
+                              (inn := !inn + 1;
                               Printf.fprintf oc "%4d %4d %4d %4d %20.12e\n"
                                 i_c k_c j_c l_c value
+                                )
+                            else
+                              out := !out + 1;
                           ) basis.(l).Contracted_shell.powers 
                       ) basis.(k).Contracted_shell.powers
                   ) basis.(j).Contracted_shell.powers
               ) basis.(i).Contracted_shell.powers;
-              with NullIntegral -> print_endline "Schwartz"; ()
+              with NullIntegral ->  ()
           done;
         done;
-      with NullIntegral -> print_endline "Big Schwartz"; ()
+      with NullIntegral -> ()
     done;
   done;
+  Printf.printf "In: %d  Out:%d\n" !inn !out ;
   close_out oc
 
 (*
diff --git a/Basis/TwoElectronRR.ml b/Basis/TwoElectronRR.ml
index 1338ba4..5124026 100644
--- a/Basis/TwoElectronRR.ml
+++ b/Basis/TwoElectronRR.ml
@@ -27,8 +27,8 @@ let hvrr_two_e m (angMom_a, angMom_b, angMom_c, angMom_d)
     | (0,0) -> zero_m_array.(m)
     | (_,0) ->
 
-      let key = [| angMom_a.(0)+1; angMom_a.(1)+1; angMom_a.(2)+1; |]
-                |> Zkey.(of_int_array ~kind:Kind_3)
+      let key = Zkey.of_int_tuple (Zkey.Three
+                                     (angMom_a.(0)+1, angMom_a.(1)+1, angMom_a.(2)+1) )
       in
 
       let (found, result) =
@@ -61,9 +61,10 @@ let hvrr_two_e m (angMom_a, angMom_b, angMom_c, angMom_d)
 
     | (_,_) ->
 
-      let key = [| angMom_a.(0)+1; angMom_a.(1)+1; angMom_a.(2)+1;
-                   angMom_c.(0)+1; angMom_c.(1)+1; angMom_c.(2)+1; |]
-                |> Zkey.(of_int_array ~kind:Kind_6)
+      let key =  Zkey.of_int_tuple (Zkey.Six
+                                      ((angMom_a.(0)+1, angMom_a.(1)+1, angMom_a.(2)+1),
+                                       (angMom_c.(0)+1, angMom_c.(1)+1, angMom_c.(2)+1)) )
+
       in
 
       let (found, result) =
@@ -110,11 +111,12 @@ let hvrr_two_e m (angMom_a, angMom_b, angMom_c, angMom_d)
     | (0,0) -> vrr m angMom_a angMom_c totAngMom_a totAngMom_c
     | (_,_) ->
 
-      let key = [| angMom_a.(0)+1; angMom_a.(1)+1; angMom_a.(2)+1;
-                   angMom_b.(0)+1; angMom_b.(1)+1; angMom_b.(2)+1;
-                   angMom_c.(0)+1; angMom_c.(1)+1; angMom_c.(2)+1;
-                   angMom_d.(0)+1; angMom_d.(1)+1; angMom_d.(2)+1; |]
-                |> Zkey.(of_int_array ~kind:Kind_12)
+      let key = Zkey.of_int_tuple (Zkey.Twelve
+                                     (( angMom_a.(0)+1, angMom_a.(1)+1, angMom_a.(2)+1),
+                                      ( angMom_b.(0)+1, angMom_b.(1)+1, angMom_b.(2)+1),
+                                      ( angMom_c.(0)+1, angMom_c.(1)+1, angMom_c.(2)+1),
+                                      ( angMom_d.(0)+1, angMom_d.(1)+1, angMom_d.(2)+1)) )
+
       in
 
       let (found, result) =
@@ -189,15 +191,6 @@ let contracted_class_shell_pairs ~zero_m ?schwartz_p ?schwartz_q shell_p shell_q
                            totAngMom shell_c, totAngMom shell_d))
   in
 
-  (*
-  (* Precomputation of overlaps *)
-  let overlaps_p =
-    Overlap.contracted_class shell_a shell_b
-  and overlaps_q =
-    Overlap.contracted_class shell_c shell_d
-  in
-  *)
-
   let contracted_class = 
     Array.make (Array.length class_indices) 0.;
   in