High-accuracy Complete Active Space multiconfiguration Dirac-Hartree-Fock calculations of hyperfine structure constants of the gold atom

TL;DR

This study uses advanced multiconfiguration Dirac-Hartree-Fock calculations to accurately determine hyperfine structure constants of gold, incorporating comprehensive electron correlation effects and deriving the nuclear quadrupole moment.

Contribution

It presents a high-accuracy CAS-based MCDHF method for hyperfine calculations of gold, including all electron correlations systematically.

Findings

Accurate hyperfine constants for gold levels obtained.

Derived nuclear quadrupole moment Q(197Au)=521.5(5.0) mb.

Method includes all electron correlations systematically.

Abstract

The multiconfiguration Dirac-Hartree-Fock (MCDHF) model has been employed to calculate the expectation values for the hyperfine splittings of the 5d96s2 2D3/2 and 5d96s2 2D5/2 levels of atomic gold. One-, two-, and three-body electron correlation effects involving all 79 electrons have been included in a systematic manner. The approximation employed in this study is equivalent to a Complete Active Space (CAS) approach. Calculated electric field gradients, together with experimental values of the electric quadrupole hyperfine structure constants, allow us to extract a nuclear electric quadrupole moment Q(197Au)=521.5(5.0) mb.