Photoelectron Spectroscopy and Electronic Structure of Heavy GroupIV-VI Diatomics
Vibrationally-resolved HeI (584{angstrom}) photoelectron spectra of the heavy group IV-VI diatomics SnSe, SnTe, PbSe, and PbTe were obtained with a new high temperature molecular beam source. Ionization potentials and spectroscopic constants are reported for all the ionic states observed. Relativistic complete active space MCSCF followed by multireference singles + doubles relativistic CI calculations which included up to 200,000 configurations were made on both the neutral diatomics and their positive ions. Ionization potentials and spectroscopic constants were calculated and were in good agreement with the experimentally-measured values. Relativistic CI potential energy curves were calculated for all the neutral ground states and the ionic states involved. Relativistic effects were shown to play an important role in these heavy diatomics. The {sup 2}{Sigma}{sub 1/2}{sup +} and {sup 2}{Pi}{sub 1/2} states for all four molecular ions showed avoided curve crossings, which resulted in pronounced shoulders in the {Omega} = 1/2 potential energy curves of PbTe{sup +}. Experimentally, autoionization transitions were also observed for the PbTe{sup +} spectrum. The importance of the relativistic effect and chemical bonding in the heavy diatomics are discussed.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 876712
- Report Number(s):
- LBL-27699; JCPSA6; TRN: US200606%%636
- Journal Information:
- Journal of Chemical Physics, Vol. 92, Issue 2; Related Information: Journal Publication Date: 01/15/1990; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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