anchor.diff:    real(rk)      :: enermax = 1e7, abscoef_thresh = 1.0d-50, abundance = 1.0d0, gf_factor = 1.0d0
     real(rk)      :: S_crit = 1e-29      ! cm/molecule, HITRAN cut-off paramater
     real(rk)      :: nu_crit = 2000.0d0  ! cm-1, HITRAN cut-off paramater
  +  real(rk)      :: ener_cut = 1e6      ! cm-1, lower energy cutoff used for partitioning into weak and strong lines
     real(rk)      :: resolving_power  = 1e6,resolving_f ! using resolving_power to set up grid
     character(len=cl) :: cutoff_model = "NONE"
     integer(ik)   :: nquad = 20      ! Number of quadrature points
  
positive.code:                 !
                  cutoff = S_crit*exp(-tranfreq/nu_crit)
                  !
                  if (abscoef>=cutoff) then
                      write(sunit,my_fmt) ilevelf,ileveli,acoef,tranfreq
                  else
                      write(wunit,my_fmt) ilevelf,ileveli,acoef,tranfreq
                  endif
                  !
                enddo
  
negative.code:               !
                call readu(w)
                !
                if (trim(w)/="ALPHA".and.(trim(w)/="NU_CRIT".and.trim(w)/="NUCRIT")) &
                   call report ("Expected: keyword = ALPHA with the switching frequency"//trim(w),.true.)
                !
                call readf(nu_crit)
                !
                if (Nitems>5) call readu(w)
                !
                if (trim(w)/="ENERCUT") &
                   call report ("Expected: keyword = ENERCUT with the switching frequency"//trim(w),.true.)
                !
                call readf(ener_cut)
                !
              case default
                !
  