diff --git a/ocaml/Input_ao_basis.ml b/ocaml/Input_ao_basis.ml
index 9754f3ec..2d7e91b3 100644
--- a/ocaml/Input_ao_basis.ml
+++ b/ocaml/Input_ao_basis.ml
@@ -46,29 +46,29 @@ end = struct
   ;;
 
   let read_ao_prim_num () =
-    (Ezfio.get_ao_basis_ao_prim_num () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_ao_basis_ao_prim_num () 
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:AO_prim_number.of_int
   ;;
 
   let read_ao_prim_num_max () =
-    (Ezfio.get_ao_basis_ao_prim_num () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_ao_basis_ao_prim_num ()
+    |> Ezfio.flattened_ezfio
     |> Array.fold ~f:(fun x y -> if x>y then x else y) ~init:0
     |> AO_prim_number.of_int
   ;;
 
   let read_ao_nucl () =
     let nmax = Nucl_number.get_max () in
-    (Ezfio.get_ao_basis_ao_nucl () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_ao_basis_ao_nucl () 
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:(fun x-> Nucl_number.of_int ~max:nmax x)
   ;;
 
   let read_ao_power () =
     let x = Ezfio.get_ao_basis_ao_power () in
     let dim = x.Ezfio.dim.(0) in
-    let data = Ezfio.flattened_ezfio_data x.Ezfio.data in
+    let data = Ezfio.flattened_ezfio x in
     let result = Array.init dim ~f:(fun x -> "") in
     for i=1 to dim
     do
@@ -83,14 +83,14 @@ end = struct
   ;;
 
   let read_ao_coef () =
-    (Ezfio.get_ao_basis_ao_coef () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_ao_basis_ao_coef () 
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:AO_coef.of_float
   ;;
 
   let read_ao_expo () =
-    (Ezfio.get_ao_basis_ao_expo () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_ao_basis_ao_expo ()
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:AO_expo.of_float
   ;;
 
diff --git a/ocaml/Input_bitmasks.ml b/ocaml/Input_bitmasks.ml
index 3f413d23..4b02a735 100644
--- a/ocaml/Input_bitmasks.ml
+++ b/ocaml/Input_bitmasks.ml
@@ -72,8 +72,8 @@ end = struct
       in
       Ezfio.set_bitmasks_generators generators
       end;
-    (Ezfio.get_bitmasks_generators ()).Ezfio.data
-    |> Ezfio.flattened_ezfio_data 
+    Ezfio.get_bitmasks_generators ()
+    |> Ezfio.flattened_ezfio
   ;;
 
   let read () = 
diff --git a/ocaml/Input_determinants.ml b/ocaml/Input_determinants.ml
index cc99c93a..b4c80b28 100644
--- a/ocaml/Input_determinants.ml
+++ b/ocaml/Input_determinants.ml
@@ -169,8 +169,8 @@ end = struct
         Ezfio.ezfio_array_of_list ~rank:1 ~dim:[| 1 |] ~data:[1.]
         |> Ezfio.set_determinants_psi_coef 
       ;
-    (Ezfio.get_determinants_psi_coef ()).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_determinants_psi_coef ()
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:Det_coef.of_float
   ;;
 
@@ -192,7 +192,7 @@ end = struct
           (Bitlist.to_int64_list det_b) ) 
         in
         Ezfio.ezfio_array_of_list ~rank:3 ~dim:[| N_int_number.to_int n_int ; 2 ; 1 |] ~data:data
-        |> Ezfio.set_determinants_psi_det 
+          |> Ezfio.set_determinants_psi_det ;
       end  ;
       (*
     let rec transform accu1 accu2 n_rest = function 
@@ -217,7 +217,7 @@ end = struct
     let n_int = N_int_number.to_int n_int in
     let psi_det_array = Ezfio.get_determinants_psi_det () in
     let dim = psi_det_array.Ezfio.dim
-    and data =  Ezfio.flattened_ezfio_data psi_det_array.Ezfio.data 
+    and data =  Ezfio.flattened_ezfio psi_det_array
     in
     assert (n_int = dim.(0));
     assert (dim.(1) = 2);
diff --git a/ocaml/Input_mo_basis.ml b/ocaml/Input_mo_basis.ml
index 1d1a9aee..d53e78b7 100644
--- a/ocaml/Input_mo_basis.ml
+++ b/ocaml/Input_mo_basis.ml
@@ -51,14 +51,13 @@ end = struct
           ~dim:[| mo_tot_num |] ~data:data
         |> Ezfio.set_mo_basis_mo_occ
       end;
-    (Ezfio.get_mo_basis_mo_occ () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.flattened_ezfio (Ezfio.get_mo_basis_mo_occ () )
     |> Array.map ~f:MO_occ.of_float
   ;;
 
   let read_mo_coef () =
-    let a = (Ezfio.get_mo_basis_mo_coef () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    let a = Ezfio.get_mo_basis_mo_coef () 
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:MO_coef.of_float
     in
     let mo_tot_num = read_mo_tot_num () |> MO_number.to_int in
diff --git a/ocaml/Input_nuclei.ml b/ocaml/Input_nuclei.ml
index 1aaa2236..5202c785 100644
--- a/ocaml/Input_nuclei.ml
+++ b/ocaml/Input_nuclei.ml
@@ -31,22 +31,22 @@ end = struct
   ;;
 
   let read_nucl_label () =
-    (Ezfio.get_nuclei_nucl_label ()).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_nuclei_nucl_label ()
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:Element.of_string 
   ;;
 
   let read_nucl_charge () =
-    (Ezfio.get_nuclei_nucl_charge () ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_nuclei_nucl_charge ()
+    |> Ezfio.flattened_ezfio
     |> Array.map ~f:Charge.of_float
   ;;
 
   let read_nucl_coord () =
     let nucl_num = Nucl_number.to_int (read_nucl_num ()) in
     let raw_data = 
-    (Ezfio.get_nuclei_nucl_coord() ).Ezfio.data
-    |> Ezfio.flattened_ezfio_data
+    Ezfio.get_nuclei_nucl_coord()
+    |> Ezfio.flattened_ezfio
     in
     let zero = Point3d.of_string Units.Bohr "0. 0. 0." in
     let result = Array.create nucl_num zero in
diff --git a/ocaml/qp_print.ml b/ocaml/qp_print.ml
index 9c2a5715..6405d0ee 100644
--- a/ocaml/qp_print.ml
+++ b/ocaml/qp_print.ml
@@ -52,8 +52,8 @@ let run_i ~action ezfio_filename =
 
   let compute_charge () =
     let input = Input.Electrons.read () in
-    let nucl_charge = Ezfio.((get_nuclei_nucl_charge ()).data)
-      |> Ezfio.flattened_ezfio_data |> Array.map ~f:(Float.to_int) 
+    let nucl_charge = Ezfio.get_nuclei_nucl_charge ()
+      |> Ezfio.flattened_ezfio |> Array.map ~f:(Float.to_int) 
     and n_alpha = input.Input.Electrons.elec_alpha_num
       |> Elec_alpha_number.to_int
     and n_beta  = input.Input.Electrons.elec_beta_num 
@@ -71,14 +71,14 @@ let run_i ~action ezfio_filename =
 
   let create_molecule () =
     let nucl_num = Ezfio.get_nuclei_nucl_num () 
-    and nucl_charge = Ezfio.((get_nuclei_nucl_charge ()).data)
-       |> Ezfio.flattened_ezfio_data
-    and nucl_coord = Ezfio.((get_nuclei_nucl_coord ()).data )
-       |> Ezfio.flattened_ezfio_data
+    and nucl_charge = Ezfio.get_nuclei_nucl_charge ()
+       |> Ezfio.flattened_ezfio
+    and nucl_coord = Ezfio.get_nuclei_nucl_coord ()
+       |> Ezfio.flattened_ezfio
     in
     let nucl_label =
       if (Ezfio.has_nuclei_nucl_label ()) then
-       Ezfio.((get_nuclei_nucl_label ()).data) |> Ezfio.flattened_ezfio_data
+       Ezfio.get_nuclei_nucl_label () |> Ezfio.flattened_ezfio
       else
         Array.map ~f:(fun x-> x
           |> Charge.of_float