The hyperfine structure of the long-lived 5D3/2 and 5D5/2 levels of Ba + ion is analyzed. A procedure for extracting relatively unexplored nuclear magnetic moments is presented. The relevant electronic matrix elements are computed in the framework of the ab initio relativistic many-body perturbation theory. Both the firstand the second-order in the hyperfine interaction corrections to the energ...

For uniform systems of spin-less fermions in d spatial dimensions with d > 1, interacting through the isotropic two-body potential v(r − r), a celebrated theorem due to Luttinger (1961) states that under the assumption of validity of the many-body perturbation theory the self-energy Σ(k; ε), with 0 ≤ k∼3kF (where kF stands for the Fermi wavenumber), satisfies the following universal asymptotic ...

Rules for obtaining transition amplitudes that are equal in length form and velocity form, order-by-order in relativistic many-body perturbation theory are presented. Explicit formulas are derived for first-, second-, and third-order amplitudes for transitions between valence states in alkali-metal atoms. Numerical codes are developed to evaluate amplitudes through third order and applied to 3s...

Based on potential-energy curves that were derived from ab initio calculations within the framework of many-body perturbation theory, mixed quantum-classical simulations have been performed to understand the dynamics of the photodesorption process of iodine from KI(100). Dissipation and recoil processes were included by adding a surface oscillator to the ab initio potentials. Using this approac...

Lead iodide perovskites have attracted considerable interest in the upcoming photovoltaic technologies and optoelectronic devices. Therefore, an accurate theoretical description of electronic optical properties especially to understand excitonic effects this class materials is scientific practical interest. However, despite several research endeavours past, most analysis key parameters for sola...