Theoretical Electronic Transition Probabilities in Diatomic Molecules II. 13‐Electron Sequence
ABSTRACT Hartree–Fock (HF) electronic dipole‐momentum and dipole‐length transition moments, M(R) and (R), respectively, are presented as a function of the internuclear distance R for the N2+(B2Σu+ − X2Σg+) first negative and (A2Πu − X2Σg>+) Meinel systems. They are compared with “experimental” M(R) and (R) curves obtained by using relative band transition probability and upper‐state lifetime measurements recently reported in the literature. Vibrational averages of both the theoretical and “experimental” transition moments are computed and used to calculate some relative band oscillator strengths fυ′υ″ / f00. The HF f00 value of 0.1370 for the first negative system differs from experiment by a factor of 5.6. For the Meinel system the HF f00 value of 1.065 × 10−2 is too large by a factor of 3.3 or 7.3 depending on whether the lifetime data of O'Neil and Davidson or that of Hollstein et al. are used to determine the experimental value. The HF transition‐moment calculations at a single value of R are also reported for the (B2Σu+ − X2Σg+) and (A2Πu − X2Σg+) systems of C2− and for the (2Πi − X2Σ+) and (2Πr − X2Σ+) systems of CN, CO+, BO, BF+, and BeF. Electronic absorption oscillator strengths are presented and compared with experiment where possible.

References (0)
 Cited In (12)

[Show abstract] [Hide abstract]
ABSTRACT: Einstein A coefficients, oscillator strengths and lifetimes have been calculated by an asymptotic expansion method, introduced by Chang and Karplus, for the N2, B 3&Pgr;g↠A 3Σ+u (first positive), C 3&Pgr;u↠B 3&Pgr;g (second positive), W 3Δu&rlarr2;B 3&Pgr;g (Wu–Benesch) and B′ 3Σ−u↠B 3&Pgr;g (infrared afterglow) band systems, using theoretical electronic transition moments, Re (r), of Yeager and McKoy. Whenever possible, comparison has been made with those calculated from the electric dipole moment functions, Re (r¯), which are functions of r¯ centroids, obtained from band intensity or lifetime measurements. Excellent agreement has been obtained in the case of the second positive band system of molecular nitrogen. However, for all other cases, conventional Re (r¯) functions are found to be superior to the theoretical Re (r) functions of Yeager and McKoy.The Journal of Chemical Physics 02/1980; 72(3). DOI:10.1063/1.439372 · 3.12 Impact Factor 
[Show abstract] [Hide abstract]
ABSTRACT: Comparative intensity measurements of C2 and C–2 molecular spectra have been made using a shock tube technique. From these measurements the absorption electronic oscillator strength of the C–2 HerzbergLagerqvist bands has been determined as 0.017 ± 0.008 at the (0,0) band origin.Journal of the Chemical Society Faraday Transactions 2 01/1973; 69:237245. DOI:10.1039/F29736900237 · 4.20 Impact Factor 
[Show abstract] [Hide abstract]
ABSTRACT: Ab initio calculations in the valence shell CI approximation have been carried out for 1Σ+g states of C2 and for doublet and quartet states of C−2 with Σ, Π and Δ symmetry. The results confirm tentative assignments made from experimental studies of the three lowest states of C−2.Chemical Physics Letters 05/1974; 26:144148. DOI:10.1016/00092614(74)891050 · 1.99 Impact Factor