diff --git a/devel/mpn/energies.irp.f b/devel/mpn/energies.irp.f
index c3a1448..d08a9ac 100644
--- a/devel/mpn/energies.irp.f
+++ b/devel/mpn/energies.irp.f
@@ -8,7 +8,7 @@ BEGIN_PROVIDER [ double precision, energy_det_i, (N_det) ]
 
  do k=1,N_det
    call bitstring_to_list(psi_det(1,1,k), list, n, N_int)
-   energy_det_i(k) = 0.d0
+   energy_det_i(k) = nuclear_repulsion
    do i=1,n
      energy_det_i(k) += fock_matrix_diag_mo(list(i))
    enddo
diff --git a/devel/mpn/mpn.irp.f b/devel/mpn/mpn.irp.f
index a988913..193fdae 100644
--- a/devel/mpn/mpn.irp.f
+++ b/devel/mpn/mpn.irp.f
@@ -18,17 +18,16 @@ program mpn
   c_pert(:,:) = 0.d0
   c_pert(1,0) = 1.d0
 
-double precision :: hij
-
+  e_pert(1) = nuclear_repulsion
   do k=1,mp_order
     ! H_ij C^(k-1)
     call h_s2_u_0_nstates_zmq(c_pert(1,k),s2,c_pert(1,k-1),1,N_det)
-    e_pert(k) = c_pert(1,k)
-    print *, k, e_pert(k), sum(e_pert) + nuclear_repulsion
+    e_pert(k) += c_pert(1,k)
+    print *, k, e_pert(k), sum(e_pert) 
 
     c_pert(1,k) = 0.d0
     c_pert(:,k) = -c_pert(:,k)
-    do l=1,k-1
+    do l=1,k
       do i=2,N_det
         c_pert(i,k) = c_pert(i,k) + e_pert(l) * c_pert(i,k-l)
       enddo