diff --git a/src/Hartree_Fock/NEEDED_MODULES b/src/Hartree_Fock/NEEDED_MODULES
index 163bdf10..4ebba314 100644
--- a/src/Hartree_Fock/NEEDED_MODULES
+++ b/src/Hartree_Fock/NEEDED_MODULES
@@ -1 +1 @@
-AOs BiInts Bitmask Electrons Ezfio_files MonoInts MOs Nuclei Output Utils
+AOs BiInts Bitmask Electrons Ezfio_files MonoInts MOGuess MOs Nuclei Output Utils 
diff --git a/src/Hartree_Fock/SCF.irp.f b/src/Hartree_Fock/SCF.irp.f
index 55c42178..9683d3c3 100644
--- a/src/Hartree_Fock/SCF.irp.f
+++ b/src/Hartree_Fock/SCF.irp.f
@@ -1,19 +1,40 @@
 
 program scf
+  call create_guess
   call orthonormalize_mos
   call run
 end
 
+subroutine create_guess
+  implicit none
+  BEGIN_DOC
+! Create an H_core guess if no MOs are present in the EZFIO directory
+  END_DOC
+  logical                        :: exists
+  PROVIDE ezfio_filename
+  call ezfio_has_mo_basis_mo_coef(exists)
+  if (.not.exists) then
+    mo_coef = ao_ortho_lowdin_coef
+    mo_label = 'Guess'
+    call mo_as_eigvectors_of_mo_matrix(mo_mono_elec_integral,size(mo_mono_elec_integral,1),size(mo_mono_elec_integral,2),mo_label)
+    SOFT_TOUCH mo_coef mo_label
+  endif
+end
+
+
 subroutine run
 
   use bitmasks
   implicit none
+  BEGIN_DOC
+! Run SCF calculation
+  END_DOC
   double precision               :: SCF_energy_before,SCF_energy_after,diag_H_mat_elem,get_mo_bielec_integral
   double precision               :: E0
   integer                        :: i_it, i, j, k
    
   E0 = HF_energy 
-  
+
   thresh_SCF = 1.d-10
   call damping_SCF
   mo_label = "Canonical"
diff --git a/src/MOs/mos.irp.f b/src/MOs/mos.irp.f
index f1158530..ce8e5272 100644
--- a/src/MOs/mos.irp.f
+++ b/src/MOs/mos.irp.f
@@ -39,14 +39,7 @@ END_PROVIDER
   logical                        :: exists
   PROVIDE ezfio_filename
   
-  !Label
-  call ezfio_has_mo_basis_mo_label(exists)
-  if (exists) then
-    call ezfio_get_mo_basis_mo_label(mo_label)
-  else
-    mo_label = 'no_label'
-  endif
-  
+
   ! Coefs
   call ezfio_has_mo_basis_mo_coef(exists)
   if (exists) then
@@ -62,8 +55,15 @@ END_PROVIDER
       enddo
     enddo
     deallocate(buffer)
+    call ezfio_has_mo_basis_mo_label(exists)
+    if (exists) then
+      call ezfio_get_mo_basis_mo_label(mo_label)
+    else
+      mo_label = 'no_label'
+    endif
   else
-    mo_coef = 0.d0
+    ! Orthonormalized AO basis
+    mo_coef = 0.
   endif
   
 END_PROVIDER