anchor.diff:      integer, intent(in) :: which_ee, which_eQ
       logical, dimension(num_conductivity_channels), intent(in) :: K_components
       real(dp) :: nn,nion, nu, nu_c, kappa_pre, ne, kF, xF, eF, Gamma_e
  +    real(dp) :: nu_n, kappa_n_pre, kFn, xFn, eFn
       
       ne = rho/amu*ionic%Ye
       kF = (threepisquare*ne)**onethird
  
positive.code:             kappa% eQ = -1.0
          end if
      end if
      if (K_components(icond_sf) .and. ionic% Yn > 0.0) then
          nn = rho*ionic% Yn/(1.0-chi)/Mneutron / density_n
          nion = (1.0-ionic%Yn)*rho/Mneutron/ionic% A /density_n
          kappa% sf =  sPh(nn,nion,T,ionic)
      end if
      kappa% total = kappa_pre/nu + kappa% sf
      
      contains
      subroutine clear_kappa()
  
negative.code:     eF = sqrt(1.0+xF**2)
      Gamma_e = Gamma/ionic%Z53
      kappa_pre = onethird*pi**2*boltzmann**2*T*ne/Melectron/eF
      kappa_n_pre = 0.0
      
      ! electrons
      call clear_kappa
      nu_c = 0.0
      nu = 0.0
  