Calculation of the hyperfine structure of Dy, Ho, Cf, and Es

TL;DR

This paper applies an advanced configuration interaction method to calculate hyperfine structures of heavy atoms Dy, Ho, Cf, and Es, aiding experimental interpretation and refining nuclear moment data.

Contribution

It introduces a new CI-based computational approach for heavy open-shell atoms and provides improved nuclear magnetic moment values for Es isotopes.

Findings

Calculated hyperfine constants for Cf and Es.

Validated calculations with lighter homologs Dy and Ho.

Revised nuclear magnetic moment of $^{253}$Es.

Abstract

A recently developed version of the configuration interaction (CI) method for open shells with a large number of valence electrons has been used to study two heavy atoms, californium (Cf, Z= 98) and einsteinium (Es, Z= 99). Motivated by experimental work to measure the hyperfine structure (HFS) for these atoms, we perform the calculations of the magnetic dipole HFS constants $A$ and electric quadrupole HFS constant $B$ for the sake of interpretation of the measurements in terms of nuclear magnetic moment $\mu$ and electric quadrupole moment $Q$. For verification of our computations, we have also carried out similar calculations for the lighter homologs dysprosium (Dy, Z= 66) and holmium (Ho, Z= 67), whose electronic structures are similar to Cf and Es, respectively. We have conducted a revision of the nuclear moments of some isotopes of Es leading to an improved value of the magnetic moment of $^{253}$Es [$\mu$($^{253}$Es) = 4.20(13)$\mu_N$].