title: The D 1Sigma+ state of 7LiH: comparison of observations with vibronic theory.
abstract: The excited D (1)Sigma(+) electronic state of (7)LiH has been observed up to near its dissociation limit by a pulsed optical-optical double resonance fluorescence depletion spectroscopic technique. An extensive vibronic calculation has been performed with a diabatic approach with purely potential couplings involving a set of eight diabatic states of (1)Sigma(+) symmetry, corresponding to seven neutral states and one ionic state. Twenty-six new vibrational levels have been observed. Both the derived vibrational energy spacings and the vibronic ones are similarly irregular. The observed spectral linewidths and vibronic resonance widths are found to vary similarly with increasing energy. Observed asymmetric spectral lineshapes may be attributed to the strong radial couplings between the discrete levels of the D (1)Sigma(+) electronic state and the continuum states of the C (1)Sigma(+) electronic state. The mutual agreement between the spectral results and the vibronic results demonstrates that the D (1)Sigma(+) electronic state of (7)LiH is better characterized by the vibronic approach.
authors.affiliation: Department of Chemistry, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Wu
authors.forename: Wei-Tzou
authors.initials: WT
authors.lastname: Luh
authors.forename: F
authors.initials: F
authors.lastname: Xavier Gadea
authors.forename: William C
authors.initials: WC
authors.lastname: Stwalley