The red bands of TaH: Identification of the ground and low-lying electronic states

Abstract

Doppler-limited laser excitation spectra were recorded for 12 bands of the molecule tantalum hydride (TaH) in the red region, covering the wavelengths 605–665 nm. These excitation bands originate from three different lower electronic states. Dispersed fluorescence experiments revealed three additional low-lying electronic states of the molecule. The identities and energies of these six states are found to be in good agreement with the multiconfiguration self-consistent field calculations of Koseki et al. (2004). The ground state is X3Φ2, with the [0.1]0+ state lying only 76 ± 6 cm−1 above it. The upper states display energy shifts caused by numerous local perturbations with other dark states.