Related papers: Reference Energies for Non-Relativistic Core Ioniz…
Green's function methods within many-body perturbation theory provide a general framework for treating electronic correlations in excited states. Here we investigate the cumulant form of the one-electron Green's function based on the…
A comprehensive study of high-accuracy photoionization cross sections is carried out using the relativistic Breit-Pauli R-matrix (BPRM) method for (hnu + Fe XVII --> Fe XVIII + e). Owing to its importance in high-temperature plasmas the…
Recently, we have introduced a new generation of effective core potentials (ECPs) designed for accurate correlated calculations but equally useful for a broad variety of approaches. The guiding principle has been the isospectrality of…
In this critical compilation, all known to us experimental data on the spectrum of neutral carbon were methodically evaluated and supplemented by parametric calculations with Cowan's code. The sources of experimental data vary from…
The correlation calculation of the electronic structure of PbH is carried out with the Generalized Relativistic Effective Core Potential (GRECP) and MultiReference single- and Double-excitation Configuration Interaction (MRD-CI) methods.…
We report an efficient implementation of the ionization potential (IP) variant of the equation-of-motion coupled cluster (IP-EOM-CC) method based on the exact two-component atomic mean field (X2CAMF) framework, utilizing Cholesky…
We discuss imaging sources from low relative-velocity correlations in heavy-ion reactions. When the correlation is dominated by interference, we can obtain the images by Fourier transforming the correlation function. In the general case, we…
We study numerically stabilization against ionization of a fully correlated two-electron model atom in an intense laser pulse. We concentrate on two frequency regimes: very high frequency, where the photon energy exceeds both, the…
The random-phase approximation to the ground state correlation energy (RPA) in combination with exact exchange (EX) has brought Kohn-Sham (KS) density functional theory one step closer towards a universal, "general purpose first principles…
High-precision QED calculations of the ground-state ionization energies are performed for all boronlike ions with the nuclear charge numbers in the range $16 \leqslant Z\leqslant 96$. The rigorous QED calculations are performed within the…
We present an implementation of relativistic ionization-potential (IP) equation-of-motion coupled-cluster (EOMCC) with up to 3-hole--2-particle (3h2p) excitations that makes use of the molecular mean-field exact two-component (mmfX2C)…
An attractive way to model nuclear quantum effects is to describe select nuclei quantum mechanically at the same level as the electrons. This non-Born-Oppenheimer (non-BO) method is known by many names including the nuclear-electronic…
We present a novel theory and implementation for computing coupled electronic and quantal nuclear subsystems on a single potential energy surface, moving beyond the standard Born-Oppenheimer (BO) separation of nuclei and electrons. We…
Atomic properties of $n=3$ states of the W$^{56+}$ $-$ W$^{61+}$ ions are systematically investigated through two state-of-the-art methods, namely, the second-order many-body perturbation theory, and the multi-configuration…
X-ray photoelectron spectroscopy (XPS) measures core-electron binding energies (CEBEs) to reveal element-specific insights into chemical environment and bonding. Accurate theoretical CEBE prediction aids XPS interpretation but requires…
For molecules and solids containing heavy elements, accurate electronic structure calculations require accounting not only for electronic correlations but also for relativistic effects. In molecules, relativity can lead to severe changes in…
We outline ideas on desired properties for a new generation of effective core potentials (ECPs) that will allow valence-only calculations to reach the full potential offered by recent advances in many-body wave function methods. The key…
The short range repulsion between nucleons is treated by a unitary correlation operator which shifts the nucleons away from each other whenever their uncorrelated positions are within the replusive core. By formulating the correlation as a…
Ar XIII is found to be unique with new features in electron-ion recombination not seen in any other ion. The ion has been studied with the unified method which provides a theoretically self-consistent set of atomic parameters for the…
Despite the fact that most quantum chemistry basis sets are designed for accurately modelling valence chemistry, these general-purpose basis sets continue to be widely used to model core-dependent properties. Core-specialised basis sets are…