State selectivity in core ionization of methane
A clear experimental signature of the population of the lowest triplet state T 1 3 of the methane dication is identified in a photoionization experiment. This state is populated only in valence ionization and is absent when the dication is formed by core ionization followed by Auger-Meitner decay. For valence ionization, the total internal energy of the CH 3 + fragment, formed during the deprotonation of CH 4 2 + , is evaluated. Notably, the distribution of this internal energy peaks at the same value regardless of the initially populated electronic state of CH 4 2 + . We find that excited electronic states of CH 3 + are predominantly populated with significant rovibrational excitation. Published by the American Physical Society 2025
Rajput, J. (ORCID:0000000157752543)↗