Spectroscopic observation of Feshbach resonances in the tellurium dimer anion.

This article focuses on the high-resolution photodetachment spectroscopy of the cryogenically cooled anionic tellurium dimer (Te₂⁻) using slow-electron velocity-map imaging (SEVI). The study precisely determines the electron affinity of neutral Te₂ as 16,689.7(92) cm⁻¹ (2.0693(11) eV) and identifies two Feshbach resonant states of Te₂⁻ located 1092(17) cm⁻¹ below and 250(11) cm⁻¹ above the photodetachment threshold. Detailed vibrational progressions and spectroscopic constants for the ground and two electronically excited states of Te₂⁻ were obtained, providing insights into autodetachment dynamics and serving as benchmarks for theoretical models. The work advances understanding of the electronic structure and resonance behavior of the tellurium dimer anion without introducing information beyond the experimental and computational results presented.