Spectroscopy of AIO: Rotational Analysis of the A2Πi-X2Σ+ Transition in the 2-μm Region

SPECTROSCOPIC CONSTANTS OF THE X1Σ+ AND 13Π STATES OF AlO+

“…These studies show that the electronic ground state has been very well characterized by infrared-optical double resonance spectroscopy (Bares et al 1985), purely rotational spectroscopy (Törring & Herrmann 1989;Yamada et al 1990;Goto et al 1994), cavity-ring down spectroscopy (Kraus et al 2002), and by analysis of its fine structure splitting (Ito 1994) and of the photoelectron spectrum of its bound negative ion, AlO − (Desai et al 1997). Ab initio computations on the low-lying electronic states of AlO are also available (McDonald & Innes 1969;Yoshimine et al 1973;Dagdigian et al 1975;Lengsfield III et al 1982;Partridge et al 1983;Ito 1994;Launila & Jonsson 1994;Gilka et al 2008;Honjou 2010). Indeed, the first calculations on the electronic structure of the AlO radical were reported by Yoshimine et al (1973) who showed that the ground state is best described by multi-configurational wavefunctions.…”

Rotational spectroscopy of AlO

“…In that work, some discrepancies were pointed out regarding their derived γ D values, as compared to those found in the microwave work. While Yamada et al (1990) had given a positive value for γ D for v = 0, the sign was in fact found to be negative in the light of high-N data of Launila et al (1994). One of the aims of the present paper is to reinvestigate this discrepancy more closely.…”

“…This is the case in Table I of Yamada et al (1990), where both J and J have been included. Goto et al (1994) only specify the "good" quantum numbers N and F in their Tables 1 and 2. In the work of Launila et al (1994) it was found that the positive sign of γ D for v = 0 was in conflict with the high-N behavior of the spin doubling of the ground state, as shown in Figs. 3 and 4 of their study.…”

“…2 of Yamada et al (1990), using the constants given by them (γ = 51.660 MHz, γ D = 0.00343 MHz), and also using the same constants, but with a reversed sign of γ D . The Hamiltonian used was the same as in Launila et al (1994). The results are presented in Fig.…”

“…Yamada et al (1990) and Goto et al (1994) recorded several ΔF = ΔN rotational transitions, resulting in a set of accurate molecular constants, including γ and γ D . Launila et al (1994) have performed a Fourier transform study of the A 2 Π i → X 2 Σ + transition of AlO in the 2 μm region. In that work, some discrepancies were pointed out regarding their derived γ D values, as compared to those found in the microwave work.…”