Theoretical oscillator strengths for infrared electronic transitions of Si2 and SiC

Abstract

view Abstract Citations (14) References (69) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Theoretical Oscillator Strengths for Infrared Electronic Transitions of SI 2 and SiC Sefyani, Fouad L. ; Schamps, Joel Abstract Ab initio calculations of the electronic transition moments for all the dipole-allowed systems connecting two valence electronic states of SiC and Si2 have been carried out using multireference configuration interaction wave functions. The 1Sigma(+) diabatic potential curves are found to exhibit an avoided crossing just in the region of equilibrium internuclear separations. The resulting configuration mixing in the Born-Oppenheimer states induces a constructive interference effect that enhances intensities of the d 1Sigma(+) - b 1Pi low-v vibronic transitions both in SiC and in Si2, but not in C2. Ab initio absolute vibronic oscillator strengths and emission probabilities are given for the d-b transitions. The calculated lifetimes of the lowest v prime levels of the d 1Sigma(+) state decrease as v prime increases, especially in SiC. At v prime = 0 they are calculated to be 8.3 microseconds in Si2 and 18.6 microseconds in SiC. Publication: The Astrophysical Journal Pub Date: October 1994 DOI: 10.1086/174786 Bibcode: 1994ApJ...434..816S Keywords: Carbon; Electron Oscillations; Electron Transitions; Infrared Radiation; Molecular Energy Levels; Silicon; Silicon Carbides; Computerized Simulation; Wave Functions; Astrophysics; MOLECULAR DATA; MOLECULAR PROCESSES full text sources ADS |