anchor.diff:        ! ADIMENSIONED critical T and S [OUTPUT]
   
         temperature(k) = temp_c_thick
  -      s(k)           = sigma_c_thick
  +      s(k)           = sigma_c_thick 
   
         ! DIMENSIONED critical T and S
         temp_thick(k)  =  temp_c_thick * state_0%T_0
  
positive.code:     character(len = 64)                                    :: fname_tot
      integer                                                :: fid_tot
      integer                                                :: ios
   ! For the critical points
      integer                                                :: index_fcp
      real(kind = x_precision)                               :: sigma_c_thick
  
negative.code:       open(fid_tot,file  = fname_tot, action='write',&
            status = 'replace', iostat = ios)
        if (ios /= 0) then
           write(*,*)"Error while opening the ", fname_tot," file."
           stop
        endif
  
        write(fid_tot,'(3(A16))') 'Surface_density', 'Temperature', 'Optical_depth'
  
        do j = 1, nb_it
          temp_real(j)  =  temp_real(j) 
          sigma_real(j) =  sigma_real(j) 
  
          call variables(temp_real(j), sigma_real(j), omega, f, optical_depth, tau_eff)
  
          temp_real(j)  =  temp_real(j) * state_0%T_0
          sigma_real(j) =  sigma_real(j) * state_0%S_0
  
          write(fid_tot,fmt = '(3(e16.6e2))') sigma_real(j), temp_real(j), tau_eff
  
  