diff --git a/src/casscf_cipsi/NEED b/src/casscf_cipsi/NEED
index dd91c7bd..11d1a78c 100644
--- a/src/casscf_cipsi/NEED
+++ b/src/casscf_cipsi/NEED
@@ -3,3 +3,4 @@ selectors_full
 generators_cas
 two_body_rdm
 dav_general_mat
+mo_optimization
diff --git a/src/mo_optimization/NEED b/src/mo_optimization/NEED
index 91f41ee3..33f770c3 100644
--- a/src/mo_optimization/NEED
+++ b/src/mo_optimization/NEED
@@ -1,7 +1,3 @@
-two_body_rdm
-hartree_fock
-cipsi
-davidson_undressed
+mo_optimization_utils
 selectors_full
 generators_full
-utils_trust_region
diff --git a/src/mo_optimization/cipsi_orb_opt.irp.f b/src/mo_optimization/cipsi_orb_opt.irp.f
index 7e3a79eb..19b3e9db 100644
--- a/src/mo_optimization/cipsi_orb_opt.irp.f
+++ b/src/mo_optimization/cipsi_orb_opt.irp.f
@@ -2,87 +2,7 @@ program optimization
   
   read_wf = .true. ! must be True for the orbital optimization !!!
   TOUCH read_wf 
-  call run_optimization
+  call run_optimization_mos_CIPSI
 
 end
 
-subroutine run_optimization
-
-  implicit none
-
-  double precision :: e_cipsi, e_opt, delta_e
-  double precision, allocatable :: Ev(:),PT2(:)
-  integer :: nb_iter,i
-  logical :: not_converged
-  character (len=100) :: filename
-
-  PROVIDE psi_det psi_coef mo_two_e_integrals_in_map ao_pseudo_integrals
-  allocate(Ev(N_states),PT2(N_states))
-
-  not_converged = .True.
-  nb_iter = 0
-
-  ! To start from the wf
-  N_det_max = max(n_det,5)
-  TOUCH N_det_max
-
-  open(unit=10, file=trim(ezfio_filename)//'/mo_optimization/result_opt')
-  write(10,*) "   Ndet        E_cipsi         E_opt          Delta_e"
-  call state_average_energy(e_cipsi)
-  write(10,'(I10, 3F15.7)') n_det, e_cipsi, e_cipsi, 0d0
-  close(10)
-
-  do while (not_converged)
-      print*,''
-      print*,'======================'
-      print*,' Cipsi step:', nb_iter
-      print*,'======================'
-      print*,'' 
-      print*,'********** cipsi step **********'
-      ! cispi calculation
-      call run_stochastic_cipsi(Ev,PT2)
-
-      ! State average energy after the cipsi step
-      call state_average_energy(e_cipsi)
-
-      print*,''
-      print*,'********** optimization step **********'
-      ! orbital optimization
-      call run_orb_opt_trust_v2
-
-      ! State average energy after the orbital optimization
-      call state_average_energy(e_opt)
-
-      print*,''
-      print*,'********** diff step **********'
-      ! Gain in energy
-      delta_e = e_opt - e_cipsi
-      print*, 'Gain in energy during the orbital optimization:', delta_e
-
-      open(unit=10, file=trim(ezfio_filename)//'/mo_optimization/result_opt', position='append')
-      write(10,'(I10, 3F15.7)') n_det, e_cipsi, e_opt, delta_e
-      close(10)
-
-      ! Exit
-      if (delta_e > 1d-12) then
-          print*, 'WARNING, something wrong happened'
-          print*, 'The gain (delta_e) in energy during the optimization process'
-          print*, 'is > 0, but it must be < 0'
-          print*, 'The program will exit'
-          exit
-      endif
-
-      if (n_det > n_det_max_opt) then
-          print*, 'The number of determinants in the wf > n_det_max_opt'
-          print*, 'The program will exit'
-          exit
-      endif
-      
-      ! To double the number of determinants in the wf
-      N_det_max = int(dble(n_det * 2)*0.9)
-      TOUCH N_det_max
-
-      nb_iter = nb_iter + 1
-  enddo
-
-end
diff --git a/src/mo_optimization/EZFIO.cfg b/src/mo_optimization_utils/EZFIO.cfg
similarity index 100%
rename from src/mo_optimization/EZFIO.cfg
rename to src/mo_optimization_utils/EZFIO.cfg
diff --git a/src/mo_optimization_utils/NEED b/src/mo_optimization_utils/NEED
new file mode 100644
index 00000000..1a78a17f
--- /dev/null
+++ b/src/mo_optimization_utils/NEED
@@ -0,0 +1,5 @@
+two_body_rdm
+hartree_fock
+cipsi
+davidson_undressed
+utils_trust_region
diff --git a/src/mo_optimization_utils/README.md b/src/mo_optimization_utils/README.md
new file mode 100644
index 00000000..94f29aee
--- /dev/null
+++ b/src/mo_optimization_utils/README.md
@@ -0,0 +1,74 @@
+# Orbital optimization
+
+## Methods  
+Different methods are available:  
+- full hessian  
+``` 
+qp set orbital_optimization optimization_method full  
+```  
+- diagonal hessian  
+``` 
+qp set orbital_optimization optimization_method diag  
+``` 
+- identity matrix  
+``` 
+qp set orbital_optimization optimization_method none  
+``` 
+
+After the optimization the ezfio contains the optimized orbitals
+ 
+## For a fixed number of determinants
+To optimize the MOs for the actual determinants:  
+``` 
+qp run orb_opt
+``` 
+ 
+## For a complete optimization, i.e, with a larger and larger wave function
+To optimize the MOs with a larger and larger wave function:  
+``` 
+qp run optimization  
+``` 
+
+The results are stored in the EZFIO in "mo_optimization/result_opt",
+with the following format:  
+(1) (2) (3) (4)  
+1: Number of determinants in the wf,  
+2: Cispi energy before the optimization,   
+3: Cipsi energy after the optimization,  
+4: Energy difference between (2) and (3).  
+ 
+The optimization process if the following: 
+- we do a first cipsi step to obtain a small number of determinants in the wf 
+- we run an orbital optimization for this wf 
+- we do a new cipsi step to double the number of determinants in the wf 
+- we run an orbital optimization for this wf 
+- ... 
+- we do that until the energy difference between (2) and (3) is  
+  smaller than the targeted accuracy for the cispi (targeted_accuracy_cipsi in qp edit) 
+  or the wf is larger than a given size (n_det_max_opt in qp_edit) 
+- after that you can reset your determinants (qp reset -d) and run a clean Cispi calculation  
+  
+### End of the optimization
+You can choos the number of determinants after what the 
+optimization will stop:
+```
+qp set orbital_optimization n_det_max_opt 1e5 # or any number
+```
+## Weight of the states
+You can change the weights of the differents states directly in qp edit.  
+It will affect ths weights used in the orbital optimization.
+
+# Tests
+To run the tests:  
+``` 
+qp test
+``` 
+
+# Org files
+The org files are stored in the directory org in order to avoid overwriting on user changes.
+The org files can be modified, to export the change to the source code, run
+```
+./TANGLE_org_mode.sh
+mv *.irp.f ../.
+```
+
diff --git a/src/mo_optimization/class.irp.f b/src/mo_optimization_utils/class.irp.f
similarity index 100%
rename from src/mo_optimization/class.irp.f
rename to src/mo_optimization_utils/class.irp.f
diff --git a/src/mo_optimization/constants.h b/src/mo_optimization_utils/constants.h
similarity index 100%
rename from src/mo_optimization/constants.h
rename to src/mo_optimization_utils/constants.h
diff --git a/src/mo_optimization/diagonal_hessian_list_opt.irp.f b/src/mo_optimization_utils/diagonal_hessian_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/diagonal_hessian_list_opt.irp.f
rename to src/mo_optimization_utils/diagonal_hessian_list_opt.irp.f
diff --git a/src/mo_optimization/diagonal_hessian_opt.irp.f b/src/mo_optimization_utils/diagonal_hessian_opt.irp.f
similarity index 100%
rename from src/mo_optimization/diagonal_hessian_opt.irp.f
rename to src/mo_optimization_utils/diagonal_hessian_opt.irp.f
diff --git a/src/mo_optimization/diagonalization_hessian.irp.f b/src/mo_optimization_utils/diagonalization_hessian.irp.f
similarity index 100%
rename from src/mo_optimization/diagonalization_hessian.irp.f
rename to src/mo_optimization_utils/diagonalization_hessian.irp.f
diff --git a/src/mo_optimization/first_diagonal_hessian_list_opt.irp.f b/src/mo_optimization_utils/first_diagonal_hessian_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_diagonal_hessian_list_opt.irp.f
rename to src/mo_optimization_utils/first_diagonal_hessian_list_opt.irp.f
diff --git a/src/mo_optimization/first_diagonal_hessian_opt.irp.f b/src/mo_optimization_utils/first_diagonal_hessian_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_diagonal_hessian_opt.irp.f
rename to src/mo_optimization_utils/first_diagonal_hessian_opt.irp.f
diff --git a/src/mo_optimization/first_gradient_list_opt.irp.f b/src/mo_optimization_utils/first_gradient_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_gradient_list_opt.irp.f
rename to src/mo_optimization_utils/first_gradient_list_opt.irp.f
diff --git a/src/mo_optimization/first_gradient_opt.irp.f b/src/mo_optimization_utils/first_gradient_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_gradient_opt.irp.f
rename to src/mo_optimization_utils/first_gradient_opt.irp.f
diff --git a/src/mo_optimization/first_hessian_list_opt.irp.f b/src/mo_optimization_utils/first_hessian_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_hessian_list_opt.irp.f
rename to src/mo_optimization_utils/first_hessian_list_opt.irp.f
diff --git a/src/mo_optimization/first_hessian_opt.irp.f b/src/mo_optimization_utils/first_hessian_opt.irp.f
similarity index 100%
rename from src/mo_optimization/first_hessian_opt.irp.f
rename to src/mo_optimization_utils/first_hessian_opt.irp.f
diff --git a/src/mo_optimization/gradient_list_opt.irp.f b/src/mo_optimization_utils/gradient_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/gradient_list_opt.irp.f
rename to src/mo_optimization_utils/gradient_list_opt.irp.f
diff --git a/src/mo_optimization/gradient_opt.irp.f b/src/mo_optimization_utils/gradient_opt.irp.f
similarity index 100%
rename from src/mo_optimization/gradient_opt.irp.f
rename to src/mo_optimization_utils/gradient_opt.irp.f
diff --git a/src/mo_optimization/hessian_list_opt.irp.f b/src/mo_optimization_utils/hessian_list_opt.irp.f
similarity index 100%
rename from src/mo_optimization/hessian_list_opt.irp.f
rename to src/mo_optimization_utils/hessian_list_opt.irp.f
diff --git a/src/mo_optimization/hessian_opt.irp.f b/src/mo_optimization_utils/hessian_opt.irp.f
similarity index 100%
rename from src/mo_optimization/hessian_opt.irp.f
rename to src/mo_optimization_utils/hessian_opt.irp.f
diff --git a/src/mo_optimization/org/TODO.org b/src/mo_optimization_utils/org/TODO.org
similarity index 100%
rename from src/mo_optimization/org/TODO.org
rename to src/mo_optimization_utils/org/TODO.org
diff --git a/src/mo_optimization/org/debug_gradient_list_opt.org b/src/mo_optimization_utils/org/debug_gradient_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/debug_gradient_list_opt.org
rename to src/mo_optimization_utils/org/debug_gradient_list_opt.org
diff --git a/src/mo_optimization/org/debug_gradient_opt.org b/src/mo_optimization_utils/org/debug_gradient_opt.org
similarity index 100%
rename from src/mo_optimization/org/debug_gradient_opt.org
rename to src/mo_optimization_utils/org/debug_gradient_opt.org
diff --git a/src/mo_optimization/org/debug_hessian_list_opt.org b/src/mo_optimization_utils/org/debug_hessian_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/debug_hessian_list_opt.org
rename to src/mo_optimization_utils/org/debug_hessian_list_opt.org
diff --git a/src/mo_optimization/org/debug_hessian_opt.org b/src/mo_optimization_utils/org/debug_hessian_opt.org
similarity index 100%
rename from src/mo_optimization/org/debug_hessian_opt.org
rename to src/mo_optimization_utils/org/debug_hessian_opt.org
diff --git a/src/mo_optimization/org/diagonal_hessian_list_opt.org b/src/mo_optimization_utils/org/diagonal_hessian_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/diagonal_hessian_list_opt.org
rename to src/mo_optimization_utils/org/diagonal_hessian_list_opt.org
diff --git a/src/mo_optimization/org/diagonal_hessian_opt.org b/src/mo_optimization_utils/org/diagonal_hessian_opt.org
similarity index 100%
rename from src/mo_optimization/org/diagonal_hessian_opt.org
rename to src/mo_optimization_utils/org/diagonal_hessian_opt.org
diff --git a/src/mo_optimization/org/diagonalization_hessian.org b/src/mo_optimization_utils/org/diagonalization_hessian.org
similarity index 100%
rename from src/mo_optimization/org/diagonalization_hessian.org
rename to src/mo_optimization_utils/org/diagonalization_hessian.org
diff --git a/src/mo_optimization/org/first_diagonal_hessian_list_opt.org b/src/mo_optimization_utils/org/first_diagonal_hessian_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_diagonal_hessian_list_opt.org
rename to src/mo_optimization_utils/org/first_diagonal_hessian_list_opt.org
diff --git a/src/mo_optimization/org/first_diagonal_hessian_opt.org b/src/mo_optimization_utils/org/first_diagonal_hessian_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_diagonal_hessian_opt.org
rename to src/mo_optimization_utils/org/first_diagonal_hessian_opt.org
diff --git a/src/mo_optimization/org/first_gradient_list_opt.org b/src/mo_optimization_utils/org/first_gradient_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_gradient_list_opt.org
rename to src/mo_optimization_utils/org/first_gradient_list_opt.org
diff --git a/src/mo_optimization/org/first_gradient_opt.org b/src/mo_optimization_utils/org/first_gradient_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_gradient_opt.org
rename to src/mo_optimization_utils/org/first_gradient_opt.org
diff --git a/src/mo_optimization/org/first_hessian_list_opt.org b/src/mo_optimization_utils/org/first_hessian_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_hessian_list_opt.org
rename to src/mo_optimization_utils/org/first_hessian_list_opt.org
diff --git a/src/mo_optimization/org/first_hessian_opt.org b/src/mo_optimization_utils/org/first_hessian_opt.org
similarity index 100%
rename from src/mo_optimization/org/first_hessian_opt.org
rename to src/mo_optimization_utils/org/first_hessian_opt.org
diff --git a/src/mo_optimization/org/gradient_list_opt.org b/src/mo_optimization_utils/org/gradient_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/gradient_list_opt.org
rename to src/mo_optimization_utils/org/gradient_list_opt.org
diff --git a/src/mo_optimization/org/gradient_opt.org b/src/mo_optimization_utils/org/gradient_opt.org
similarity index 100%
rename from src/mo_optimization/org/gradient_opt.org
rename to src/mo_optimization_utils/org/gradient_opt.org
diff --git a/src/mo_optimization/org/hessian_list_opt.org b/src/mo_optimization_utils/org/hessian_list_opt.org
similarity index 100%
rename from src/mo_optimization/org/hessian_list_opt.org
rename to src/mo_optimization_utils/org/hessian_list_opt.org
diff --git a/src/mo_optimization/org/hessian_opt.org b/src/mo_optimization_utils/org/hessian_opt.org
similarity index 100%
rename from src/mo_optimization/org/hessian_opt.org
rename to src/mo_optimization_utils/org/hessian_opt.org
diff --git a/src/mo_optimization/org/my_providers.org b/src/mo_optimization_utils/org/my_providers.org
similarity index 100%
rename from src/mo_optimization/org/my_providers.org
rename to src/mo_optimization_utils/org/my_providers.org
diff --git a/src/mo_optimization/org/optimization.org b/src/mo_optimization_utils/org/optimization.org
similarity index 100%
rename from src/mo_optimization/org/optimization.org
rename to src/mo_optimization_utils/org/optimization.org
diff --git a/src/mo_optimization/org/orb_opt_trust_v2.org b/src/mo_optimization_utils/org/orb_opt_trust_v2.org
similarity index 100%
rename from src/mo_optimization/org/orb_opt_trust_v2.org
rename to src/mo_optimization_utils/org/orb_opt_trust_v2.org
diff --git a/src/mo_optimization/org/state_average_energy.org b/src/mo_optimization_utils/org/state_average_energy.org
similarity index 100%
rename from src/mo_optimization/org/state_average_energy.org
rename to src/mo_optimization_utils/org/state_average_energy.org
diff --git a/src/mo_optimization/org/state_weight_normalization.org b/src/mo_optimization_utils/org/state_weight_normalization.org
similarity index 100%
rename from src/mo_optimization/org/state_weight_normalization.org
rename to src/mo_optimization_utils/org/state_weight_normalization.org
diff --git a/src/mo_optimization/org/update_parameters.org b/src/mo_optimization_utils/org/update_parameters.org
similarity index 100%
rename from src/mo_optimization/org/update_parameters.org
rename to src/mo_optimization_utils/org/update_parameters.org
diff --git a/src/mo_optimization/org/update_st_av_ci_energy.org b/src/mo_optimization_utils/org/update_st_av_ci_energy.org
similarity index 100%
rename from src/mo_optimization/org/update_st_av_ci_energy.org
rename to src/mo_optimization_utils/org/update_st_av_ci_energy.org
diff --git a/src/mo_optimization_utils/routine_opt_mos.irp.f b/src/mo_optimization_utils/routine_opt_mos.irp.f
new file mode 100644
index 00000000..fceba2c5
--- /dev/null
+++ b/src/mo_optimization_utils/routine_opt_mos.irp.f
@@ -0,0 +1,81 @@
+
+subroutine run_optimization_mos_CIPSI
+
+  implicit none
+
+  double precision :: e_cipsi, e_opt, delta_e
+  double precision, allocatable :: Ev(:),PT2(:)
+  integer :: nb_iter,i
+  logical :: not_converged
+  character (len=100) :: filename
+
+  PROVIDE psi_det psi_coef mo_two_e_integrals_in_map ao_pseudo_integrals
+  allocate(Ev(N_states),PT2(N_states))
+
+  not_converged = .True.
+  nb_iter = 0
+
+  ! To start from the wf
+  N_det_max = max(n_det,5)
+  TOUCH N_det_max
+
+  open(unit=10, file=trim(ezfio_filename)//'/mo_optimization/result_opt')
+  write(10,*) "   Ndet        E_cipsi         E_opt          Delta_e"
+  call state_average_energy(e_cipsi)
+  write(10,'(I10, 3F15.7)') n_det, e_cipsi, e_cipsi, 0d0
+  close(10)
+
+  do while (not_converged)
+      print*,''
+      print*,'======================'
+      print*,' Cipsi step:', nb_iter
+      print*,'======================'
+      print*,'' 
+      print*,'********** cipsi step **********'
+      ! cispi calculation
+      call run_stochastic_cipsi(Ev,PT2)
+
+      ! State average energy after the cipsi step
+      call state_average_energy(e_cipsi)
+
+      print*,''
+      print*,'********** optimization step **********'
+      ! orbital optimization
+      call run_orb_opt_trust_v2
+
+      ! State average energy after the orbital optimization
+      call state_average_energy(e_opt)
+
+      print*,''
+      print*,'********** diff step **********'
+      ! Gain in energy
+      delta_e = e_opt - e_cipsi
+      print*, 'Gain in energy during the orbital optimization:', delta_e
+
+      open(unit=10, file=trim(ezfio_filename)//'/mo_optimization/result_opt', position='append')
+      write(10,'(I10, 3F15.7)') n_det, e_cipsi, e_opt, delta_e
+      close(10)
+
+      ! Exit
+      if (delta_e > 1d-12) then
+          print*, 'WARNING, something wrong happened'
+          print*, 'The gain (delta_e) in energy during the optimization process'
+          print*, 'is > 0, but it must be < 0'
+          print*, 'The program will exit'
+          exit
+      endif
+
+      if (n_det > n_det_max_opt) then
+          print*, 'The number of determinants in the wf > n_det_max_opt'
+          print*, 'The program will exit'
+          exit
+      endif
+      
+      ! To double the number of determinants in the wf
+      N_det_max = int(dble(n_det * 2)*0.9)
+      TOUCH N_det_max
+
+      nb_iter = nb_iter + 1
+  enddo
+
+end
diff --git a/src/mo_optimization/run_orb_opt_trust_v2.irp.f b/src/mo_optimization_utils/run_orb_opt_trust_v2.irp.f
similarity index 100%
rename from src/mo_optimization/run_orb_opt_trust_v2.irp.f
rename to src/mo_optimization_utils/run_orb_opt_trust_v2.irp.f
diff --git a/src/mo_optimization/save_energy.irp.f b/src/mo_optimization_utils/save_energy.irp.f
similarity index 100%
rename from src/mo_optimization/save_energy.irp.f
rename to src/mo_optimization_utils/save_energy.irp.f
diff --git a/src/mo_optimization/state_average_energy.irp.f b/src/mo_optimization_utils/state_average_energy.irp.f
similarity index 100%
rename from src/mo_optimization/state_average_energy.irp.f
rename to src/mo_optimization_utils/state_average_energy.irp.f
diff --git a/src/mo_optimization/state_weight_normalization.irp.f b/src/mo_optimization_utils/state_weight_normalization.irp.f
similarity index 100%
rename from src/mo_optimization/state_weight_normalization.irp.f
rename to src/mo_optimization_utils/state_weight_normalization.irp.f
diff --git a/src/mo_optimization/update_parameters.irp.f b/src/mo_optimization_utils/update_parameters.irp.f
similarity index 100%
rename from src/mo_optimization/update_parameters.irp.f
rename to src/mo_optimization_utils/update_parameters.irp.f
diff --git a/src/mo_optimization/update_st_av_ci_energy.irp.f b/src/mo_optimization_utils/update_st_av_ci_energy.irp.f
similarity index 100%
rename from src/mo_optimization/update_st_av_ci_energy.irp.f
rename to src/mo_optimization_utils/update_st_av_ci_energy.irp.f