Stretch-Bender Calculations of the Rovibronic Energies in the Excited, Ã2A1, Electronic State of NH2 and of the Near-Resonant High-Lying Levels of the X̃2B1 State

✍ Scribed by Geoffrey Duxbury; Alexander Alijah

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 266 KB
• Volume: 211
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2001.8481

✦ Synopsis

The extended stretch-bender Hamiltonian, incorporating spin-orbit coupling and overall rotation, has been used to calculate the spin-vibronic structure of the rovibronic energies in the region where the vibronic states of the excited à 2 A 1 electronic state of NH 2 interact with near-resonant high-lying levels of the X 2 B 1 state of NH 2 . A detailed comparison has been made with the experimental measurements which were made of these rovibronic states, the majority of which are due to Ramsay, Vervloet, and their collaborators. We have shown that, as in our study of the vibronic levels of the X 2 B 1 state below the barrier to linearity, in order to fit the variation of the effective vibronic spin-orbit coupling constant over the whole of this energy regime, the effective linear molecule spin-orbit coupling constant, A SO must be increased from the earlier value of 50 cm -1 of Ch. Jungen, K.-E. J. Hallin, and A. Merer (Mol. Phys. 40, 65-94 (1980)) to 61.6 cm -1 . The impact of Fermi resonance, in both the Ã2 A 1 and X 2 B 1 states, on the observed rovibronic structure has been assessed. The pattern of calculated spin-rovibronic levels, including the effects of spin uncoupling, is in good agreement with that measured experimentally.