diff --git a/src/PROPERTIES/properties_energy.irp.f b/src/PROPERTIES/properties_energy.irp.f
index 357b21d..7f42053 100644
--- a/src/PROPERTIES/properties_energy.irp.f
+++ b/src/PROPERTIES/properties_energy.irp.f
@@ -270,7 +270,9 @@ BEGIN_PROVIDER [ double precision, E_loc_zv ]
  BEGIN_DOC
  ! Zero-variance parameter on E_loc
  END_DOC
-   E_loc_zv  = E_loc + (E_trial-E_loc) * dmc_zv_weight
+   E_loc_zv = E_loc 
+   E_loc_zv += (E_trial-E_loc) * dmc_zv_weight
+!   E_loc_zv += - time_step*(E_trial**2 + 1.44341217940434 - E_loc**2)*dmc_zv_weight
 !  E_loc_zv(3)  = dmc_zv_weight_half
 !  E_loc_zv(:)  = 0.d0
 
diff --git a/src/SAMPLING/pdmc_step.irp.f b/src/SAMPLING/pdmc_step.irp.f
index 0efb370..9c9b4a8 100644
--- a/src/SAMPLING/pdmc_step.irp.f
+++ b/src/SAMPLING/pdmc_step.irp.f
@@ -109,9 +109,9 @@ END_SHELL
  endif
 
   integer :: info
-  double precision :: H(0:pdmc_n_diag/2,0:pdmc_n_diag/2), S(0:pdmc_n_diag/2,0:pdmc_n_diag/2), w(0:pdmc_n_diag/2), work(3*pdmc_n_diag+1) 
-  H = 0.d0
-  S = 0.d0
+!  double precision :: H(0:pdmc_n_diag/2,0:pdmc_n_diag/2), S(0:pdmc_n_diag/2,0:pdmc_n_diag/2), w(0:pdmc_n_diag/2), work(3*pdmc_n_diag+1) 
+!  H = 0.d0
+!  S = 0.d0
 
  do while (loop)
 
@@ -234,13 +234,13 @@ END_SHELL
     block_weight += pdmc_pop_weight_mult(pdmc_n_diag) * pdmc_weight(i_walk)
 
     pdmc_pop_weight_mult(0) = 1.d0/pdmc_weight(i_walk)
-    do k=0,pdmc_n_diag/2
-      do l=0,pdmc_n_diag/2
-        H(k,l) += E_loc*pdmc_pop_weight_mult(k+l) * pdmc_weight(i_walk)
-        S(k,l) += pdmc_pop_weight_mult(k+l) * pdmc_weight(i_walk)
-      enddo
-    enddo
-    H = H + (E_trial - E_loc)
+!    do k=0,pdmc_n_diag/2
+!      do l=0,pdmc_n_diag/2
+!        H(k,l) += E_loc*pdmc_pop_weight_mult(k+l) * pdmc_weight(i_walk)
+!        S(k,l) += pdmc_pop_weight_mult(k+l) * pdmc_weight(i_walk)
+!      enddo
+!    enddo
+!    H = H + (E_trial - E_loc)
 
 !  else
 !     pdmc_weight(i_walk) = 1.d0