allow to detect four electrons in coincidence correctly. An effect of site-specific excitation, if any, can thus only be found in the relative abundance of the different fragmentation pathways. Table \[tab:yields\] shows the yield of the four fragmentation pathways discussed in the previous section, normalized to the total ion yield (measured via the total number of events).

  detected fragments                                                                                          
  ------------------------------------------------------ ------------------------------ --------------------- ---------------------
                                                         305.0 eV                       299.0 eV              286.9 eV
  {CH${}^{+}$, CF${}_{3}^{+}$, Cl${}^{+}$, Br${}^{+}$}   $3.9 \cdot 10^{-5}$            $2.7 \cdot 10^{-5}$   $4.7 \cdot 10^{-5}$
  {CH${}^{+}$, CF${}_{2}^{+}$, Cl${}^{+}$, Br${}^{+}$}   $1.8 \cdot 10^{-4}$            $1.2 \cdot 10^{-4}$   $2.1 \cdot 10^{-4}$
  {H${}^{+}$, CF${}_{3}^{+}$, Cl${}^{+}$, Br${}^{+}$}    $\mathbf{1.2 \cdot 10^{-4}}$   $3.4 \cdot 10^{-5}$   $3.2 \cdot 10^{-5}$
  {H${}^{+}$, CF${}_{2}^{+}$, Cl${}^{+}$, Br${}^{+}$}    $\mathbf{2.8 \cdot 10^{-4}}$   $2.9 \cdot 10^{-5}$   $6.4 \cdot 10^{-5}$

  : Yield of different four-body fragmentation pathways normalized to the total number of events. The relative yield of the first two pathways does not change when going above the carbon 1s ionization threshold. The fragmentation pathways with a detected proton are slightly enhanced when C${}_{\mathrm{F}}$ can be photoionized (bold font).[]{data-label="tab:yields"}

The first two break-ups, involving a CH${}^{+}$ ion do not show significant dependence of the photon energy. The break-ups where a proton was detected seem to have a higher 