Observation of the shallow [Formula: see text] state of NaH

Chia-Ching Chu; Hsien-Yu Huang; Hsiang-Chin Lin; Yi-Hsiang Hsiao; Thou-Jen Whang; Chin-Chun Tsai

doi:10.1063/1.5065460

Observation of the shallow $2 {}^{1}Π$ state of NaH

J Chem Phys. 2019 Jan 14;150(2):024303. doi: 10.1063/1.5065460.

Authors

Chia-Ching Chu¹, Hsien-Yu Huang¹, Hsiang-Chin Lin¹, Yi-Hsiang Hsiao¹, Thou-Jen Whang¹, Chin-Chun Tsai²

Affiliations

¹ Department of Chemistry, National Cheng Kung University, Tainan 70101, Taiwan.
² Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.

PMID: 30646708
DOI: 10.1063/1.5065460

Abstract

The 2 ¹Π state of NaH has been observed up to the last bound vibrational level using pulsed optical-optical double resonance fluorescence depletion spectroscopy. A total of 20 rovibrational energy levels ( $v$ = 2-4 and J = 1-9) were assigned to this electronic state by means of comparing the successive rovibrational spectra to the eigenvalues of the ab initio potential energy curve. The decrease of background fluorescence near the atomic asymptotic limit Na(3d) + H(1s) is an indication of reaching the dissociation limit of the NaH 2 ¹Π state. Unobserved rovibrational levels ( $v$ = 0 and 1) are due to poor Franck-Condon overlap of 2 ¹Π ← A ¹Σ⁺ transition within the accessible rovibrational levels of intermediate A ¹Σ⁺ state of this work.