Anomalous structure in the A 6Σ+-X 6Σ+ transition of MnO caused by interference between two internal hyperfine perturbations

Microwave spectrum of the MnO radical in the X 6Σ+ state

“…[4][5][6][7][8] The rotational, centrifugal distortion, spin-spin coupling, spin-rotation coupling, and the two main hyperfine coupling constants agree well with those obtained by intermodulated fluorescence spectroscopy. 8 Eight minor molecular constants: three hyperfine ͓C I (Mn), b S (Mn), and eQq(Mn)͔; two higher-order fine structure ͑␥ S and ⌰͒; and three centrifugal distortion ͑ D , ␥ D , and b FD ͒ were determined.…”

“…They found a new type of perturbation due to a mixing of spin components through hyperfine matrix elements, and the observed extra lines due to this mixing made it possible to determine the fine structure parameters for the two electronic states. Recently Adam et al 8 studied the same electronic transition at sub-Doppler resolution using intermodulated fluorescence spectroscopy. They found an anomalous structure, which was explained by internal hyperfine perturbations in both electronic states and reported revised molecular constants for the X 6 ⌺ ϩ vϭ0 state and the A 6 ⌺ ϩ vϭ1 state.…”

Nuclear hyperfine structure in the X3Σ+ state of 91ZrC

“…One of these pairs consists of the levels with J ¼ N AE 1=2 which, as indicated, are coupled directly through the hyperfine Hamiltonian. Sizeable perturbations of this type occur between the F 3 and F 4 electron spin components of the X 6 R þ state of MnO [37].…”

“…The larger of the two magnetic hyperfine parameters is the contact parameter, b, though the effects of the dipolar parameter, c, are not negligible. In fact, evaluation of explicit matrix elements of the dipolar interaction [37] shows that, although its effects normally diminish with increasing rotation, they become important again at an internal perturbation, and that this can allow the parameter c to be determined with greater precision.…”

Laser Absorption Spectroscopy of LaF+: Ligand Field Assignment of States in the Range 0–4 eV

“…High-resolution spectra were recorded using a tuning Table 2. 4 Notation from the ligand field theory calculation (see Table 3). Low-lying states of La 2/ ( n l ) F 0 ( õ4 eV ) correlate with the La 2/ nl Å 5 d , 4 f, 6s, and 6 p configurations.…”