diff --git a/ocaml/qptypes_generator.ml b/ocaml/qptypes_generator.ml
index aa6bd533..d76120b8 100644
--- a/ocaml/qptypes_generator.ml
+++ b/ocaml/qptypes_generator.ml
@@ -214,6 +214,26 @@ end = struct
     | _ -> raise (Invalid_argument (\"Wrong IO type : \"^s))
 
 end
+
+module Perturbation : sig
+  type t [@@deriving sexp]
+  val to_string : t -> string
+  val of_string : string -> t
+end = struct
+  type t = 
+  | EN
+  | Barycentric
+  [@@deriving sexp]
+
+  let to_string = function
+  | EN -> \"EN\"
+  | Barycentric -> \"Barycentric\"
+  let of_string  s = 
+    match (String.lowercase_ascii s) with
+    | \"en\"  -> EN
+    | \"barycentric\" -> Barycentric
+    | _ -> raise (Invalid_argument (\"Wrong Perturbation type : \"^s))
+end
 "
 
 
diff --git a/plugins/Full_CI_ZMQ/energy.irp.f b/plugins/Full_CI_ZMQ/energy.irp.f
index a8361b2d..72895a1d 100644
--- a/plugins/Full_CI_ZMQ/energy.irp.f
+++ b/plugins/Full_CI_ZMQ/energy.irp.f
@@ -12,11 +12,17 @@ BEGIN_PROVIDER [ double precision, pt2_E0_denominator, (N_states) ]
  ! E0 in the denominator of the PT2
  END_DOC
  if (initialize_pt2_E0_denominator) then
- pt2_E0_denominator(1:N_states) = psi_energy(1:N_states)
+   if (h0_type == "EN") then
+     pt2_E0_denominator(1:N_states) = psi_energy(1:N_states)
+   else if (h0_type == "Barycentric") then
+     pt2_E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
+   else
+     print *,  h0_type, ' not implemented'
+     stop
+   endif
 ! call ezfio_get_full_ci_zmq_energy(pt2_E0_denominator(1))
 ! pt2_E0_denominator(1) -= nuclear_repulsion
 ! pt2_E0_denominator(1:N_states) = HF_energy - nuclear_repulsion
-!  pt2_E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
   call write_double(6,pt2_E0_denominator(1)+nuclear_repulsion, 'PT2 Energy denominator')
  else
    pt2_E0_denominator = -huge(1.d0)
diff --git a/plugins/Perturbation/EZFIO.cfg b/plugins/Perturbation/EZFIO.cfg
index 7120e4a6..8c56b03a 100644
--- a/plugins/Perturbation/EZFIO.cfg
+++ b/plugins/Perturbation/EZFIO.cfg
@@ -62,4 +62,9 @@ doc: Thresholds on selectors (fraction of the norm) for final PT2 calculation
 interface: ezfio,provider,ocaml
 default: 1.
 
+[h0_type]
+type: Perturbation
+doc: Type of zeroth-order Hamiltonian [ EN | Barycentric ]
+interface: ezfio,provider,ocaml
+default: EN
 
diff --git a/plugins/shiftedbk/EZFIO.cfg b/plugins/shiftedbk/EZFIO.cfg
new file mode 100644
index 00000000..c8dbb19e
--- /dev/null
+++ b/plugins/shiftedbk/EZFIO.cfg
@@ -0,0 +1,22 @@
+[energy]
+type: double precision
+doc: Calculated energy
+interface: ezfio
+
+[thresh_dressed_ci]
+type: Threshold
+doc: Threshold on the convergence of the dressed CI energy
+interface: ezfio,provider,ocaml
+default: 1.e-5
+
+[n_it_max_dressed_ci]
+type: Strictly_positive_int
+doc: Maximum number of dressed CI iterations
+interface: ezfio,provider,ocaml
+default: 10
+
+[h0_type]
+type: Perturbation
+doc: Type of zeroth-order Hamiltonian [ EN | Barycentric ]
+interface: ezfio,provider,ocaml
+default: EN
diff --git a/plugins/shiftedbk/shifted_bk_routines.irp.f b/plugins/shiftedbk/shifted_bk_routines.irp.f
index aae25315..e88d153c 100644
--- a/plugins/shiftedbk/shifted_bk_routines.irp.f
+++ b/plugins/shiftedbk/shifted_bk_routines.irp.f
@@ -82,11 +82,14 @@ BEGIN_PROVIDER [ double precision, E0_denominator, (N_states) ]
   ! E0 in the denominator of the PT2
   END_DOC
   if (initialize_E0_denominator) then
-   E0_denominator(1:N_states) = psi_energy(1:N_states)
- ! call ezfio_get_full_ci_zmq_energy(pt2_E0_denominator(1))
- ! E0_denominator(1) -= nuclear_repulsion
- ! E0_denominator(1:N_states) = HF_energy - nuclear_repulsion
- ! E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
+   if (h0_type == "EN") then
+     E0_denominator(1:N_states) = psi_energy(1:N_states)
+   else if (h0_type == "Barycentric") then
+     E0_denominator(1:N_states) = barycentric_electronic_energy(1:N_states)
+   else
+     print *,  h0_type, ' not implemented'
+     stop
+   endif
   else
     E0_denominator = -huge(1.d0)
   endif