arXiv subjects

Krzysztof Strasburger

Publications and source records attributed to Krzysztof Strasburger.

4 recordsLinked to original sources

arXiv2026

Electrical and optical dipole polarizabilities of two lowest triplet states of the beryllium atom

High-accuracy static and dynamic polarizabilities of the $2^3P_u$ and $^{3}S_{g}$ states of the neutral beryllium atom are reported. The calculations employed explicitly correlated Gaussian (ECG) basis sets, and first-order wave functions were obtained by minimization of the Hylleraas functional. The final basis sets used for the response-property calculations contained c.a. 7000-8000 functions, depending on the polarizability component and the chosen symmetry. The results cover frequencies from the static limit, $ω= 0$, up to the third resonance for the $2^{3}P_{u}$ state and up to the second resonance for the $3^{3}S_{g}$ state. To the best of our knowledge, these are the first calculations of dynamic and static polarizabilities for these excited states of the beryllium atom using explicitly correlated basis sets.

physics.atom-ph↗

arXiv2026

Bosonic content of three-fermion highest-spin states

A rigorous characterization of the information content of any highest-spin three-fermion wave function is presented. It is based upon a formal decomposition of the wave function into a finite set of fixed invariants, called shapes, whose sole purpose is to satisfy the Pauli principle, and a variable part, constituting the bosonic excitations of these invariants, that provides its physical content. As an example, this decomposition is applied to a benchmark-quality approximate wave function of the lowest-energy quartet electronic state of the lithium atom. This wave function, which comprises hundreds of basis functions, is reduced to eleven shape blocks, only five of which are numerically significant. Such a compact characterization is a generic example of the appearance of superselection rules in configuration space, and provides a qualitative aid in the search for robust few-particle entangled states.

quant-ph↗

arXiv2020

Energy difference between the lowest doublet and quartet states states of the boron atom

The energies of the lowest $^2P_u$, $^4P_g$ and $2D_g$ states of the boron atom are calculated with $μ$hartree accuracy, in the basis of symmetrized, explicitly correlated Gaussian lobe functions. Finite nuclear mass and scalar relativistic corrections are taken into account. This study contributes to the problem of the energy differences between doublet and quartet states of boron, which have not been measured to date. It is found that the $^2P_u\rightarrow^4P_g$ excitation energy, recommended in the Atomic Spectra Database, appears underestimated by more than 300~cm$^{-1}$.

physics.chem-ph↗

arXiv2020

Explicitly correlated wavefunctions of the ground state and the lowest quintuplet state of the carbon atom

Variational, nonrelativisitic energies have been calculated for the ground state ($^3P_g$) and the lowest quintuplet state ($^5S_u$) of the carbon atom, with wavefunctions expressed in the basis of symmetry-projected, explicitly correlated Gaussian (ECG) lobe functions. New exact limits of these energies have been estimated, amounting to $-37.844906(4)$ and $-37.691751(2)$ hartree. With finite nuclear masses and leading, scalar relativistic corrections included, respective experimental excitation energy of $^{12}C$ has been reproduced with accuracy of about 7 cm$^{-1}$.

physics.chem-ph↗