- Hyperfine structure in high spin multiplicity electronic states: Analysis of the B 4Π-X 4Σ- transition of gaseous NbO
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The (0,0) band of the B 4Π-X 4Σ- transition of NbO, near 6600 Angstroem, has been analyzed from spectra taken at sub-Doppler resolution.The transition is notable for the great width of its Nb nuclear hyperfine structure, which is caused principally by the unpaired 5s? electron in the ground state interacting with the large magnetic moment of the 9341Nb nucleus (I=9/2).A fit to the ground-state combination differences, including four very precise microwave lines measured by Suenram et al. , has given a comprehensive set of rotational, spin, and hyperfine parameters.Prominent among these are the third-order spin-orbit distortions of the spin-rotation interaction and the Fermi contact interaction, which are large and well determined, reflecting different degrees of spin-orbit contamination of the 4Σ-1/2 and 4Σ-3/2 components of the ground state.The δ2?B 4Π state was hard to fit, for a number of reasons.First, its spin-orbit structure is asymmetric, because of strong perturbations by a 2Π state which has been identified in this work, from among the various weak bands in the NbO spectrum near 7000 Angstroem; the result is that many high order centrifugal distortion terms are needed in an effective Hamiltonian model for the rotation.Second, the hyperfine structure is perturbed, not only by this 2Π state, but by distant Σ and Δ states at higher energy.The ??2?* C 4Σ- state at 21 350 cm-1 appears to be one of these.The distant states generate large apparent nuclear spin-rotation interactions, both within and between the Λ components of the Π state, as a result of cross terms between matrix elements of the operators -2BJ*L and aI*L.Similar cross terms arising from the operators AL*S and aI*L produce corrections to the Fermi contact matrix elements and are responsible for the unexpected negative sign of the magnetic hyperfine parameter d.The off-diagonal quadrupole parameter e2Qq2 is very large, and causes some of the higher J line shapes of the B-X system to be noticeably asymmetric at Doppler limited resolution; its value is consistent with the electron configuration of the B 4Π state being δ 2?.
- Adam, A. G.,Azuma, Y.,Barry, J. A.,Merer, A. J.,Sassenberg, U.,et al.
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- Reactions of group V metal atoms with water molecules. Matrix isolation FTIR and quantum chemical studies
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Laser-ablated group V metal atoms (V, Nb, Ta) were co-deposited with water molecules in excess argon. The V atoms reacted with water to form the inserted HVOH molecule spontaneously. The Nb atoms reacted with water to form the NbOH2 complex and
- Zhou,Dong,Zhang,Qin
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p. 135 - 141
(2007/10/03)
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