anchor.diff:               index_orb_act_mono(idx(jdet),4) = list_act_reverse(exc(1,1,2))   !!!  a_a
                index_orb_act_mono(idx(jdet),5) = list_act_reverse(exc(1,2,2))   !!!  a^{\dagger}_{b}
                index_orb_act_mono(idx(jdet),6) = 2
  -           ! print*, '******************'
  -           ! call debug_det(psi_det(1,1,idet),N_int)
  -           ! call debug_det(psi_det(1,1,idx(jdet)),N_int)
  -           ! print*, 'h1,p1,s1 = ',index_orb_act_mono(idx(jdet),1),index_orb_act_mono(idx(jdet),2), index_orb_act_mono(idx(jdet),3)
  -           ! print*, 'h2,p2,s2 = ',index_orb_act_mono(idx(jdet),4),index_orb_act_mono(idx(jdet),5), index_orb_act_mono(idx(jdet),6)
  -           ! print*, '******************'
  -           ! pause
             endif
            else
             index_orb_act_mono(idx(jdet),1) = -1
  
positive.code: !!!!!!!!!!!!!!!!!!!!!!!!!!! determination of the connections between I and the other J determinants mono excited in the CAS
  !!!!!!!!!!!!!!!!!!!!!!!!!!!! the determinants I and J must be connected by the following operator 
  !!!!!!!!!!!!!!!!!!!!!!!!!!!! <Jdet | a^{\dagger}_b a_{a}  | Idet> 
         do jdet = 1, idx(0)
           if(idx(jdet).ne.idet)then
  !         print*, degree(jdet)
  
negative.code:                  ! | det_tmp_bis > = a^{\dagger}_{borb,kspin} a_{aorb,kspin} | det_tmp > 
                   call do_mono_excitation(det_tmp_bis,list_act(aorb),list_act(borb),kspin,i_ok)
                   if(i_ok .ne. 1)cycle
                   call get_mono_excitation(det_tmp,det_tmp_bis,exc,phase,N_int)
  
                   ! < det_tmp     | H | det_tmp_bis >  = F_{aorb,borb}
  !                call i_H_j(det_tmp_bis,det_tmp,N_int,hab)
                   hab = fock_operator_local(aorb,borb,kspin) * phase  
                   ! < jdet | H | det_tmp_bis > = phase * (ir|cv)
  !                call i_H_j(det_tmp_bis,psi_det(1,1,idx(jdet)),N_int,hja)
                   call get_double_excitation(det_tmp_bis,psi_det(1,1,idx(jdet)),exc,phase,N_int)
  