A High‐Resolution¹⁸O Isotope Study in the Vacuum Ultraviolet of theA¹Π →X¹Σ⁺4th Positive System of CO

Perturbations in the A1Π,v= 0 state of12C18O investigated via complementary spectroscopic techniques

“…Our new measurements, with uncertainties between about 0.001 and 0.02 cm −1 , enable the determination of more constants defining the A(0) and perturber levels than previously, and with better precision. All comparable parameters show consistency between this work and that of Beaty et al [12], given their estimated uncertainties, apart from the A(0) and d(4) term origins and the η A(0) ∼ d (4) interaction parameter. The T v discrepancies likely arise from correlation of this parameter with high-order rotational constants and our inclusion of an additional constant, H, relative to Beaty et al [12].…”

“…However, this statistical uncertainty is smaller than the 0.001 cm −1 absolute frequency uncertainty of our data (tied to the REMPI-laser experiment) and we conclude that the estimated uncertainty of T 0 is 0.001 cm −1 . We list all residual differences of laser-measured and modelled frequencies in Table 1 [12] based on comprehensive emission spectra of A−X(0, 0) and extra lines from perturbing states, with their deperturbed constants also listed in Table 7. A similar scale of experimental information was used in that previous work but with frequency uncertainties of 0.05 cm −1 or more.…”

“…https://doi.org/./.. absorption via the A 1 ← X 1 + system using vacuumultraviolet (VUV) absorption [10][11][12]. These experiments reveal multiple non-Born-Oppenheimer interactions of the A 1 state with several other states, which do not themselves readily appear in experimental spectra: d 3 , e 3 − , a 3 + , D 1 , and I 1 − .…”

“…These experiments reveal multiple non-Born-Oppenheimer interactions of the A 1 state with several other states, which do not themselves readily appear in experimental spectra: d 3 , e 3 − , a 3 + , D 1 , and I 1 − . Previously, Beaty et al [12] used their high-resolution A 1 → X 1 + emission spectra to model the interaction of the A 1 (v = 0 − 9) levels with these states and deduced deperturbed molecular constants. VUV-laser excitation studies on the A 1 → X 1 + system for 12 C 18 O have been performed as well [13,14].…”

Commission 14: Atomic and Molecular Data: (Donnees Atomiques et Moleculaires)

“…Tunable picosecond lasers have been used to measure lifetimes in the E'IIt; = 0 and v = 1 states of three isotopic varieties of CO (Cacciani et al 1998). High-resolution spectroscopy has been performed on the A-X system in 1 2 C 1 8 0 (Beaty et al 1997). The EUV spectrum of CO excited by electron impact has been studied at high resolution (Ciocca, Kanik & Ajello 1997), as well as the A-X system (Beegle et al 1999).…”