High-Resolution Study of theX21 →X10+Fine-Structure Transition of BiF

Rotational analysis of the (57,0) band of the triplet–singlet transition in Hg2 produced in a free-jet expansion beam

“…The HF splitting, is described by anãI Á J a term, whereã is a coupling constant describing the interaction (it simplifies toãI z J az , where I z and J az are the I and J a components along the internuclear axis). In some couplings (mostly Hund's cases (a) and (c)), the HF splitting of the rotational energy levels decreases as J increases, as was observed for the a1 state in 207 Pb 16 O ( 3 R + 1 R + transition) [28] or the X 2 1-X 1 0 + (X 3 R À ) system in 209 Bi 19 F [29]. For the former, the first-order HF splitting due to the magnetic dipole-dipole interaction changes as 2J þ1…”

Born-Oppenheimer breakdown effects and hyperfine structure in the rotational spectra of SbF and SbCl

“…They pointed out that the measured values of both nuclear quadrupole coupling constants and nuclear spin-rotation constants are really effective values including contributions from electronnuclear hyperfine constants. This difference was also noted by Fink et al in their definitive high resolution near-infrared study of the X 2 1 À X 1 0 + fine structure transition of BiF [23].…”

Experimental and Theoretical Study of the Electronic States and Spectra of BiNa

“…High-resolution spectra (0.02 cm Ϫ1 ) show that the bands of the 9350 cm Ϫ1 system consist of P and R branches only, whereas the 7600 cm Ϫ1 system contains P, Q, and R branches (Figs Seven bands of the A 2 3 X 1 (0 -0, 0 -1, 1-0, 1-1, 1-2, 2-1, 2-3) and five bands of the A 2 3 X 2 (0 -0, 0 -1, 1-1, 1-2, 2-3) systems were measured at high resolution (0.02 cm Ϫ1 ) and rotationally analyzed. In the spectra of BiH and BiF, magnetic hyperfine splitting in the X 2 1 state leads to strong hfs splitting of the low J lines of all transitions ending in this state (2,4). Except for a weak broadening of the low J lines in the Q and R branches, no such hfs splitting is observed in the A 2 3 X 2 bands of BiNa (Fig.…”

“…3 Numbers in parentheses are the standard deviations of the parameters in units of the last digit. 4 Data marked with a star were fixed in the fit.…”

“…3 From the fit of the A 2 0 ϩ 3 X 3 ⌺ Ϫ bands. 4 These data obtained from the fit of the A 2 0 ϩ 3 X 1 0 ϩ bands were fixed in the fits of the A 2 0 ϩ 3 X 2 1 and A 2 0 ϩ 3 X 3 ⌺ Ϫ bands.…”