Supplemental Material

Detailed computational information is provided, including structure searches, optimized geometries and relative energies of low-lying CLixHy+ isomers, vibrational frequency analyses, and high-level single-point energy calculations. Additional bonding analyses (NBO, AdNDP, and EDA-NOCV), Born-Oppenheimer molecular dynamics simulations, deformation density plots, and complete Cartesian coordinates are also included.