Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5415959 | Journal of Molecular Spectroscopy | 2007 | 17 Pages |
Abstract
We have calculated the three-dimensional potential energy surfaces for the 1 2Aâ² and 1 2Aâ³ states of BrCN+ at the MR-SDCI_DK+Q/[QZP-ANO-RCC (Br, C, N)] level of theory, where MR-SDCI_DK means 'multi-reference single and double excitation configuration interaction calculation with Douglas-Kroll Hamiltonian.' These ab initio potential energy surfaces have a common minimum (corresponding to the XË2Î state) at a linear equilibrium structure with re(Br-C)Â =Â 1.735Â Ã
and re(C-N)Â =Â 1.199Â Ã
. Variational RENNER calculations yield a zero-point averaged structure (with the structural parameters calculated as expectation values over rovibrational wavefunctions) with ãr(Br-C)ã0Â =Â 1.739Â Ã
, ãr(C-N)ã0Â =Â 1.204Â Ã
, and ãâ (Br-C-N)ã0 = 172(4)°. A severe Fermi resonance between 2ν2 and ν3 has been found theoretically for the 2Aâ³ potential energy surface. Comparing the ab initio zero-point averaged structure with a recent, experimentally derived r0 structure, it is concluded that the effects of large-amplitude bending motion should be taken into account explicitly in the process of deriving the r0 structure from the experimental values of the rotational constants. The electronic structure of XË2Î BrCN+ has also been discussed.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Tsuneo Hirano, Rei Okuda, Umpei Nagashima, Yoshihiro Nakashima, Keiichi Tanaka, Per Jensen,