We do not observe any conclusive recoil-frame covariance features for this fragment. However, this might also be due to it displaying the strongest distortion of the ion VMI among all fragments, which makes the center determination for this ion complicated. The momentum distribution map for this ion has three dissociation channels that can be interpreted as (1,0), (1,1), and (1,2) or as (2,0), (2,1), and (2,2) (see Equation ), which does not favor either of the interpretations. However, the TOF-MS data is more in favor of the C + interpretation of this peak: we see two peaks that are positioned at m/z = 12 and m/z = 13 (Figure ). This pattern suggests that this feature corresponds to C + because, in case of the dication, we would expect m/z = 12 for C 2 , m/z = 12.5 for C 2 H 2+ , and m/z = 13.0 for C 2 H 2+ 2 . The isotope C in this case does not explain the observed pattern since, in the natural abundance, it is expected to be around 1% of the most intense peak, while the ratio of the peaks at m/z = 12 and m/z = 13 is about 2:1, respectively (Figure ).