Distribution of magnetic dipole strength — binning

In previous papers, we examined the systematics of magnetic dipole transitions in a single [Formula: see text] shell. We here extend the study to large space calculations. We consider the nuclei [Formula: see text]Ti, [Formula: see text]Ti and [Formula: see text]Cr. In this paper, we focus on the [Formula: see text] strength as a function of excitation of energy. The initial state is the lowest [Formula: see text] state in a specified nucleus. The final states are [Formula: see text] [Formula: see text], all in one plot, and [Formula: see text] [Formula: see text] in another. The initial figures have points all over the map although there is a suggestion of an exponential trend. To reduce clutter, we perform binning operations in which the summed strength in a given energy interval is represented by a single point. The new binning curves show more clearly the exponential fall of [Formula: see text]’s with energy.

The full infrared spectrum of molecular hydrogen

Context. The high spectral resolution R ∼ 45 000 provided by IGRINS (Immersion Grating INfrared Spectrometer) at MacDonald Observatory and R ∼ 100 000 achieved by CRIRES (CRyogenic high-resolution InfraRed Echelle Spectrograph) at VLT (Very Large Telescope) challenges the present knowledge of infrared spectra. Aims. We aim to predict the full infrared spectrum of molecular hydrogen at a comparable accuracy. Methods. We take advantage of the recent theoretical ab initio studies on molecular hydrogen to compute both the electric quadrupole and magnetic dipole transitions taking place within the ground electronic molecular state of hydrogen. Results. We computed the full infrared spectrum of molecular hydrogen at an unprecedented accuracy and derive for the first time the emission probabilities including both electric quadrupole (ΔJ = 0, ±2) and magnetic dipole transitions (ΔJ = 0) as well as the total radiative lifetime of each rovibrational state. Inclusion of magnetic dipole transitions increases the emission probabilities by factors of a few for highly excited rotational levels, which occur in the 3–20 μ range.

The spin and orbital contributions to magnetic dipole transitions

In previous works, we examined the systematics of magnetic dipole transitions in a single j shell. We here extend the study to large space calculations. We consider the nuclei [Formula: see text]Ti, [Formula: see text]Ti and [Formula: see text]Cr. Of particular interest are the contributions to [Formula: see text] of the spin and orbital parts of the magnetic dipole operator. Whereas usual scissors mode analyses have as an initial state the [Formula: see text] ground state (of an even-even nucleus), we here start with the lowest [Formula: see text] state. This enables us to reach many more states, e.g., [Formula: see text] 1, and 2 and thus get a better picture of the collectivity of this state.

Relations between the aromaticity and magnetic dipole transitions in the electronic spectra of hetero[8]circulenes

Magnetically induced current densities have been calculated at the second-order Møller–Plesset perturbation theory (MP2) level for seven hetero[8]circulenes and their dicationic and dianionic forms.

Isoscalar and isovector spin responses in p-shell and sd-shell nuclei

We study the spin magnetic dipole transitions in sd-shell even-even nuclei with N=Z and a p-shell nucleus 12C by modern shell model calculations. The shell model wave functions take into account enhanced isoscalar (IS) spin-triplet pairing as well as the effective spin operators. We point out that the IS pairing and the effective spin operators give a large quenching effect on the isovector (IV) spin transitions to be consistent with observed data by (p, p′) experiments. On the other hand, the observed IS spin strengths do not show large quenching effect suggested by the calculated investigation. The IS pairing gives a substantial quenching effect on the spin magnetic dipole transitions, especially on the IV ones.