Fourier transform emission spectroscopy of the A(2)Pi-X-2 Sigma(+) transition of BeD

C Focsa, P F Bernath, R Mitzner, R Colin

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The A(2)Pi-X(2)Sigma(+) Delta upsilon = 0 sequence of BeD was observed in the 19500-20800 cm(-1) spectral region using a Fourier transform spectrometer. The emission spectrum was excited in a Be hollow cathode discharge lamp with a He/D, gas mixture. The observed lines were assigned to the 0-0 to 6-6 bands. The Delta upsilon = -1 sequence was too weak to be seen in our Fourier transform spectra. We therefore used a previously recorded but unpublished are emission spectrum to identify the: 0-1 to 5-6 by = -1 bands. Consequently, all of the diagonal bands could be linked together and the vibrational intervals determined. The Delta upsilon = 0 and Delta upsilon = -1 data were fitted together in a global fit and effective constants derived. Using the information available from the study of the C(2)Sigma(+)-X(2)Sigma(+) system [R. Colin, C. Dreze, and M. Steinhauer, Can, J. Phys. 61, 641 (1983)], the upsilon = 8-12 vibrational levels of the ground state were added in a Dunham fit. A set of Dunham Y constants was determined for the X(2)Sigma(+) state along with traditional equilibrium parameters for the A(2)Pi excited state. The equilibrium bond lengths were found to be 1.341742(5) Angstrom for the ground state and 1.33309(4) Angstrom. for the excited state. A reanalysis of the previously published A(2)Pi-X(2)Sigma(+) 0-0 to 3-3 Delta upsilon = 0 bands of BeT [D. De Greef and R. Colin, J. Mel. Spectrosc. 53, 455-465 (1974)] was also performed. (C) 1998 Academic Press.

Original languageEnglish
Pages (from-to)348-358
Number of pages11
Issue number2
Publication statusPublished - Dec 1998



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