Experimental evidence for anomalous nuclear delocalization inC2H3+

Abstract
The structure of protonated acetylene (C2 H3+), including correlations, is measured and analyzed by an advanced Coulomb explosion imaging method. In the data analysis, it is essential to include large-amplitude motions of the nuclei within the molecule and many-body correlation features for revealing the correct structure. We find that the nuclear conformations in this molecule differ markedly from theoretical predictions and previous experimental findings.