diff --git a/src/SAMPLING/dmc_step.irp.f b/src/SAMPLING/dmc_step.irp.f
index 769a91d..ca5f703 100644
--- a/src/SAMPLING/dmc_step.irp.f
+++ b/src/SAMPLING/dmc_step.irp.f
@@ -86,19 +86,29 @@ END_SHELL
  call system_clock(cpu0, count_rate, count_max)
  cpu2 = cpu0
  do while (loop)
+  ! Move to the next projection step
   dmc_projection_step = mod(dmc_projection_step+1,dmc_projection)+1
 
+  ! Remove contribution of the old value of the weight at the new
+  ! projection step
   pop_weight_mult *= 1.d0/pop_weight(dmc_projection_step)
+
+  ! Compute the new weight of the population
   pop_weight(dmc_projection_step) = 0.d0
   do k=1,walk_num
     pop_weight(dmc_projection_step) += dmc_weight(k)
   enddo
 
+  ! Normalize the weight of the walkers by the weight of the population
   do k=1,walk_num
     dmc_weight(k) = dmc_weight(k)/pop_weight(dmc_projection_step)
   enddo
 
+  ! Normalize the weight of the population at the current projection step by
+  ! the number of walkers
   pop_weight(dmc_projection_step) = pop_weight(dmc_projection_step)/dble(walk_num)
+
+  ! Update the running population weight
   pop_weight_mult *= pop_weight(dmc_projection_step)
 
 BEGIN_SHELL [ /usr/bin/python ]
diff --git a/src/SAMPLING/vmc_step.irp.f b/src/SAMPLING/vmc_step.irp.f
index 0cac8d2..d22021b 100644
--- a/src/SAMPLING/vmc_step.irp.f
+++ b/src/SAMPLING/vmc_step.irp.f
@@ -178,6 +178,17 @@ END_SHELL
    enddo
    
    if (qmc_method == t_DMC) then
+!     if ( (trapped_walk(i_walk) < trapped_walk_max).and. &
+!          (psi_value * psi_value_save(i_walk) > 0.d0).and. &
+!          (dabs(E_ref-E_loc)*time_step_sq < -.2d0*E_ref) ) then
+     if ( (trapped_walk(i_walk) < trapped_walk_max).and. &
+          (psi_value * psi_value_save(i_walk) >= 0.d0) ) then
+       dmc_weight(i_walk) = dexp(dtime_step*(E_ref - E_loc))
+     else
+       dmc_weight(i_walk) = 0.d0
+       trapped_walk(i_walk) = 0
+     endif
+
      psi_value_save(i_walk) = psi_value
      !DIR$ VECTOR ALIGNED
      !DIR$ LOOP COUNT (200)
@@ -187,22 +198,10 @@ END_SHELL
        psi_grad_psi_inv_save(i,3,i_walk) = psi_grad_psi_inv_z(i) 
      enddo
 
-!     if ( (trapped_walk(i_walk) < trapped_walk_max).and. &
-!          (psi_value * psi_value_save(i_walk) > 0.d0).and. &
-!          (dabs(E_ref-E_loc)*time_step_sq < -.2d0*E_ref) ) then
-     if ( (trapped_walk(i_walk) < trapped_walk_max).and. &
-          (psi_value * psi_value_save(i_walk) > 0.d0) ) then
-       dmc_weight(i_walk) = exp(time_step*(E_ref - E_loc))
-
-     else
-       dmc_weight(i_walk) = 0.d0
-       trapped_walk(i_walk) = 0
-     endif
    endif
  
  enddo
 
-
  double precision               :: factor
  factor = 1.d0/block_weight
  SOFT_TOUCH block_weight