MRCI study of the photoelectron spectrum of GeC and GeSi and their GeC+ and GeSi+ ions

摘要

The lowest-lying states of the species GeC, GeC+, GeSi, and GeSi+ were studied using the multireference configuration interaction (MRCI) method and the aug-cc-pVQZ basis set. For the first time, the GeC+ molecule was characterized. The dissociation energy (D-o) of the ground state (X-3 Pi) of GeC is equal to 3.70 eV, showing good agreement with the theoretical result (3.90 eV) of Sari and colleagues. These results, however, are considerably smaller than the experimental value of 4.72 eV. The dissociation energy of the ground state (X-3 Sigma(-)) of GeSi is equal to 2.90 eV, and it is in very good agreement with the experimental value (3.08 eV). The most favorable transitions are A(3)Sigma(-) (GeC) --> X-4 Sigma(-) (GeC+), A(3)Sigma(-) (GeC) --> b(2)Pi (GeC+) and X-3 Sigma(-) (GeSi) --> X-4 Sigma(-) (GeSi+), which present very few peaks in the spectra. (C) 2006 Wiley Periodicals, Inc.