diff --git a/ezfio_config/qmc.config b/ezfio_config/qmc.config
index 29aaac9..3789a8b 100644
--- a/ezfio_config/qmc.config
+++ b/ezfio_config/qmc.config
@@ -64,6 +64,7 @@ simulation
   ci_threshold        double precision
   md5_key             character*(32)
   E_ref               double precision
+  E_trial             double precision
   srmc_projection_time real
 
 jastrow
diff --git a/ocaml/Input.ml b/ocaml/Input.ml
index 894754b..6a1ff43 100644
--- a/ocaml/Input.ml
+++ b/ocaml/Input.ml
@@ -490,6 +490,63 @@ end
 
 
 
+module Trial_wf_energy : sig
+
+  type t = float
+  val doc : string
+  val read  : unit -> t
+  val write : t -> unit
+  val to_float  : t -> float 
+  val of_float  : float -> t
+  val to_string : t -> string
+  val of_string : string -> t
+
+end = struct
+
+  type t = float
+  let doc = "Energy of the trial wave function (au)"
+
+  let of_float x = 
+    if (x > 0.) then
+      failwith "Reference energy should not be positive.";
+    if (x <= -1_000_000.) then
+      failwith "Reference energy is too low.";
+    x
+
+
+  let to_float x = x
+
+  let read () = 
+    let _ =
+      Lazy.force Qputils.ezfio_filename
+    in
+    if (not (Ezfio.has_simulation_e_trial ())) then
+      to_float 0.
+      |> Ezfio.set_simulation_e_trial;
+    Ezfio.get_simulation_e_trial ()
+    |> of_float
+
+
+  let write t =
+    let _ =
+      Lazy.force Qputils.ezfio_filename
+    in
+    to_float t
+    |> Ezfio.set_simulation_e_trial
+
+
+  let of_string x =
+     Float.of_string x
+     |> of_float
+
+
+  let to_string x =
+    to_float x 
+    |> Float.to_string 
+
+
+end
+
 module Ref_energy : sig
 
   type t = float
diff --git a/ocaml/Qmcchem_edit.ml b/ocaml/Qmcchem_edit.ml
index 2f6a6e7..bcad9c7 100644
--- a/ocaml/Qmcchem_edit.ml
+++ b/ocaml/Qmcchem_edit.ml
@@ -24,6 +24,7 @@ type field =
  | Method
  | Sampling
  | Ref_energy
+ | Trial_wf_energy
  | CI_threshold
  | Time_step
  | SRMC_projection_time 
@@ -62,6 +63,8 @@ let get field =
    option_to_string Sampling.read     Sampling.to_string     Sampling.doc  
  | Ref_energy   ->
    option_to_string Ref_energy.read   Ref_energy.to_string   Ref_energy.doc  
+ | Trial_wf_energy ->
+   option_to_string Trial_wf_energy.read   Trial_wf_energy.to_string   Trial_wf_energy.doc  
  | CI_threshold ->                    
    option_to_string CI_threshold.read   CI_threshold.to_string   CI_threshold.doc  
  | Time_step    ->                    
@@ -105,7 +108,7 @@ let write_input_in_ezfio  ezfio_filename  fields =
 
 
 (** Run the edit command *)
-let run ~c ?f ?t ?l ?m ?e ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_filename =
+let run ~c ?f ?t ?l ?m ?e ?et ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_filename =
 
   let interactive = ref (
     if c then
@@ -130,18 +133,19 @@ let run ~c ?f ?t ?l ?m ?e ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_filename =
     in ();
   in
 
-  handle_option     Input.Ref_energy.(of_float , write) e;
-  handle_option   Input.Jastrow_type.(of_string, write) j;
-  handle_option     Input.Block_time.(of_int   , write) l;
-  handle_option         Input.Method.(of_string, write) m;
-  handle_option      Input.Stop_time.(of_int   , write) t;
-  handle_option       Input.Sampling.(of_string, write) s;
-  handle_option Input.Fitcusp_factor.(of_float , write) f;
-  handle_option      Input.Time_step.(of_float , write) ts;
-  handle_option       Input.Walk_num.(of_int   , write) w;
-  handle_option   Input.Walk_num_tot.(of_int   , write) wt;
-  handle_option   Input.CI_threshold.(of_float , write) n;
-  handle_option   Input.SRMC_projection_time.(of_float , write) p;
+  handle_option      Input.Ref_energy.(of_float , write) e;
+  handle_option Input.Trial_wf_energy.(of_float , write) et;
+  handle_option    Input.Jastrow_type.(of_string, write) j;
+  handle_option      Input.Block_time.(of_int   , write) l;
+  handle_option          Input.Method.(of_string, write) m;
+  handle_option       Input.Stop_time.(of_int   , write) t;
+  handle_option        Input.Sampling.(of_string, write) s;
+  handle_option  Input.Fitcusp_factor.(of_float , write) f;
+  handle_option       Input.Time_step.(of_float , write) ts;
+  handle_option        Input.Walk_num.(of_int   , write) w;
+  handle_option    Input.Walk_num_tot.(of_int   , write) wt;
+  handle_option    Input.CI_threshold.(of_float , write) n;
+  handle_option Input.SRMC_projection_time.(of_float , write) p;
                  
 
   let fields = 
@@ -153,6 +157,7 @@ let run ~c ?f ?t ?l ?m ?e ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_filename =
       Time_step            ;
       SRMC_projection_time  ;
       Ref_energy           ;
+      Trial_wf_energy      ;
       Walk_num             ;
       Walk_num_tot         ;
       Fitcusp_factor       ;
@@ -225,6 +230,7 @@ let run ~c ?f ?t ?l ?m ?e ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_filename =
             |  Walk_num_tot          ->  Walk_num_tot.(of_string         s  |>  write)
             |  CI_threshold          ->  CI_threshold.(of_string         s  |>  write)
             |  Jastrow_type          ->  Jastrow_type.(of_string         s  |>  write)
+            |  Trial_wf_energy       ->  Trial_wf_energy.(of_string      s  |>  write)
             |  Properties            ->  Properties.(of_string           s  |>  write)
          end
        with
@@ -281,6 +287,8 @@ let spec =
      ~doc:("method "^Input.Method.doc)
   +> flag "e"  (optional float)
      ~doc:("energy "^Input.Ref_energy.doc)
+  +> flag "et"  (optional float)
+     ~doc:("energy "^Input.Trial_wf_energy.doc)
   +> flag "s"  (optional string)
      ~doc:("sampling "^Input.Sampling.doc)
   +> flag "ts"  (optional float)
@@ -307,8 +315,8 @@ let command =
 Edit input data
       ")
     spec
-    (fun c f t l m e s ts w wt n j p ezfio_file input () -> 
-      run ~c ?f ?t ?l ?m ?e ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_file )
+    (fun c f t l m e et s ts w wt n j p ezfio_file input () -> 
+      run ~c ?f ?t ?l ?m ?e ?et ?s ?ts ?w ?wt ?n ?j ?p ?input ezfio_file )
 
 
 
diff --git a/src/PROPERTIES/properties_energy.irp.f b/src/PROPERTIES/properties_energy.irp.f
index 1924d49..4dd387f 100644
--- a/src/PROPERTIES/properties_energy.irp.f
+++ b/src/PROPERTIES/properties_energy.irp.f
@@ -253,7 +253,7 @@ BEGIN_PROVIDER [ double precision, E_loc_zv ]
  BEGIN_DOC
  ! Zero-variance parameter on E_loc
  END_DOC
- E_loc_zv = E_loc
+ E_loc_zv = E_trial
 END_PROVIDER
 
 
diff --git a/src/SAMPLING/pdmc_step.irp.f b/src/SAMPLING/pdmc_step.irp.f
index 9b3758b..592c1a9 100644
--- a/src/SAMPLING/pdmc_step.irp.f
+++ b/src/SAMPLING/pdmc_step.irp.f
@@ -174,7 +174,7 @@ END_SHELL
 
     if (calc_E_loc_zv) then
       if (dabs(pdmc_weight(i_walk)*pop_weight_mult) > 1.d-6) then
-        E_loc_zv  = E_loc + (E_ref-E_loc)/(pdmc_weight(i_walk)*pop_weight_mult)
+        E_loc_zv  = E_loc + (E_trial-E_loc)/(pdmc_weight(i_walk)*pop_weight_mult)
       else
         E_loc_zv = 0.d0
       endif
diff --git a/src/ezfio_interface.irp.f b/src/ezfio_interface.irp.f
index 08c9cfe..0bb76be 100644
--- a/src/ezfio_interface.irp.f
+++ b/src/ezfio_interface.irp.f
@@ -45,6 +45,7 @@ data = [ \
 ("simulation_http_server"          , "character*(128)", ""                      ),
 ("simulation_md5_key"              , "character*(32)" , ""                     ),
 ("simulation_e_ref"                , "double precision" , ""                   ),
+("simulation_e_trial"              , "double precision" , ""                   ),
 ("simulation_do_run"               , "logical       " , ""                   ),
 ("pseudo_do_pseudo"         , "logical       " , ""                   ),
 
diff --git a/src/simulation.irp.f b/src/simulation.irp.f
index ceb66d9..d3ba571 100644
--- a/src/simulation.irp.f
+++ b/src/simulation.irp.f
@@ -365,3 +365,11 @@ BEGIN_PROVIDER [ character*(32), md5_key ]
    endif
 END_PROVIDER
 
+BEGIN_PROVIDER [ double precision, E_trial ]
+ implicit none
+ BEGIN_DOC
+ ! Energy of the trial wave function
+ END_DOC
+ call get_simulation_e_trial(E_trial)
+END_PROVIDER
+