diff --git a/ocaml/Input.ml b/ocaml/Input.ml
index 9d5f6b7f..df14af68 100644
--- a/ocaml/Input.ml
+++ b/ocaml/Input.ml
@@ -12,5 +12,6 @@ include Input_determinants;;
 include Input_electrons;;
 include Input_full_ci;;
 include Input_hartree_fock;;
+include Input_mo_basis;;
 
 
diff --git a/ocaml/Input_mo_basis.ml b/ocaml/Input_mo_basis.ml
new file mode 100644
index 00000000..fab7810a
--- /dev/null
+++ b/ocaml/Input_mo_basis.ml
@@ -0,0 +1,88 @@
+open Qptypes;;
+open Qputils;;
+open Core.Std;;
+
+module Mo_basis : sig
+  type t = 
+    { mo_tot_num      : MO_number.t ;
+      mo_label        : Non_empty_string.t;
+      mo_occ          : Positive_float.t array;
+      mo_coef         : MO_coef.t array;
+    }
+  ;;
+  val read : unit -> t
+  val to_string : t -> string
+end = struct
+  type t = 
+    { mo_tot_num      : MO_number.t ;
+      mo_label        : Non_empty_string.t;
+      mo_occ          : Positive_float.t array;
+      mo_coef         : MO_coef.t array;
+    }
+  ;;
+
+  let get_default = Qpackage.get_ezfio_default "mo_basis";;
+
+  let read_mo_label () = 
+    if not (Ezfio.has_mo_basis_mo_label ()) then
+       Ezfio.set_mo_basis_mo_label "Unknown"
+    ;
+    Ezfio.get_mo_basis_mo_label ()
+    |> Non_empty_string.of_string
+  ;;
+
+  let read_mo_tot_num () =
+    Ezfio.get_mo_basis_mo_tot_num ()
+    |> MO_number.of_int
+  ;;
+
+  let read_mo_occ () =
+    if not (Ezfio.has_mo_basis_mo_label ()) then
+      begin
+        let elec_alpha_num = Ezfio.get_electrons_elec_alpha_num () 
+        and elec_beta_num = Ezfio.get_electrons_elec_beta_num ()
+        and mo_tot_num = MO_number.to_int (read_mo_tot_num ()) in
+        let data = Array.init mo_tot_num ~f:(fun i ->
+          if (i<elec_beta_num) then 2.
+          else if (i < elec_alpha_num) then 1.
+          else 0.) |> Array.to_list in
+        Ezfio.ezfio_array_of_list ~rank:1 
+          ~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
+    |> Array.map ~f:Positive_float.of_float
+  ;;
+
+  let read_mo_coef () =
+    (Ezfio.get_mo_basis_mo_coef () ).Ezfio.data
+    |> Ezfio.flattened_ezfio_data
+    |> Array.map ~f:MO_coef.of_float
+  ;;
+
+  let read () =
+    { mo_tot_num      = read_mo_tot_num ();
+      mo_label        = read_mo_label () ;
+      mo_occ          = read_mo_occ ();
+      mo_coef         = read_mo_coef ();
+    }
+  ;;
+
+  let to_string b =
+    Printf.sprintf "
+mo_label        = %s
+mo_tot_num      = \"%s\"
+mo_occ          = %s
+mo_coef         = %s
+"
+    (Non_empty_string.to_string b.mo_label)
+    (MO_number.to_string b.mo_tot_num)
+    (b.mo_occ |> Array.to_list |> List.map
+      ~f:(Positive_float.to_string) |> String.concat ~sep:", " )
+    (b.mo_coef |> Array.to_list |> List.map
+      ~f:(MO_coef.to_string) |> String.concat ~sep:", " )
+
+end
+
+
diff --git a/ocaml/test_input.ml b/ocaml/test_input.ml
index b88cd37c..6b02f02e 100644
--- a/ocaml/test_input.ml
+++ b/ocaml/test_input.ml
@@ -61,6 +61,13 @@ let test_hf () =
   print_endline (Input.Hartree_fock.to_string b);
 ;;
 
+let test_mo () =
+  Ezfio.set_file "F2.ezfio" ;
+  let b = Input.Mo_basis.read ()
+  in
+  print_endline (Input.Mo_basis.to_string b);
+;;
+
 (*
 test_hf ();;
 test_ao ();;
@@ -68,5 +75,6 @@ test_bielec_intergals ();;
 test_bitmasks ();
 test_cis ();
 test_dets ();
-*)
 test_cisd_sc2 ();
+*)
+test_mo ();;