Quadrupole moments and hyperfine constants of metastable states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, Hg{sup +}, and Au
Abstract
Atomic quadrupole moments and hyperfine constants of the metastable {sup 2}D{sub 3/2,5/2} states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, and Hg{sup +} are calculated by the multiconfiguration DiracHartreeFock and relativistic configurationinteraction methods. For Hg{sup +}, the configuration is 5d{sup 9}6s{sup 2}. For the other ions, the configuration consists of a single delectron outside a set of closed shells. Current interest in the quadrupole moments of these states is due to the fact that optical transitions of these ions may be useful as references for frequency standards. Energy shifts of the metastable states due to the interactions of the quadrupole moments with external electric field gradients are among the largest sources of error in these frequency standards. For the quadrupole moments, agreement is obtained to within about 10% with the available measurements. For the hyperfine constants, good agreement is obtained with measurements and with other calculations, except for the A factors of the {sup 2}D{sub 5/2} states of Sr{sup +}, Ba{sup +}, and Yb{sup +}, where the correlation effects are so large that they reverse the sign of the constant relative to the DiracHartreeFock value. As a test of the Hg{sup +} calculational methods, quadrupole moments and hyperfinemore »
 Authors:
 Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)
 Publication Date:
 OSTI Identifier:
 20974571
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.73.022510; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; BARIUM IONS; CALCIUM IONS; COMPUTER CALCULATIONS; CORRELATIONS; DIRAC APPROXIMATION; DIRAC EQUATION; ELECTRIC FIELDS; ELECTRONIC STRUCTURE; ELECTRONS; GOLD 197; GOLD IONS; HARTREEFOCK METHOD; HYPERFINE STRUCTURE; INTERACTIONS; MERCURY IONS; METASTABLE STATES; QUADRUPOLE MOMENTS; SHELLS; STRONTIUM IONS; YTTERBIUM IONS
Citation Formats
Itano, Wayne M. Quadrupole moments and hyperfine constants of metastable states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, Hg{sup +}, and Au. United States: N. p., 2006.
Web. doi:10.1103/PHYSREVA.73.022510.
Itano, Wayne M. Quadrupole moments and hyperfine constants of metastable states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, Hg{sup +}, and Au. United States. doi:10.1103/PHYSREVA.73.022510.
Itano, Wayne M. Wed .
"Quadrupole moments and hyperfine constants of metastable states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, Hg{sup +}, and Au". United States.
doi:10.1103/PHYSREVA.73.022510.
@article{osti_20974571,
title = {Quadrupole moments and hyperfine constants of metastable states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, Hg{sup +}, and Au},
author = {Itano, Wayne M.},
abstractNote = {Atomic quadrupole moments and hyperfine constants of the metastable {sup 2}D{sub 3/2,5/2} states of Ca{sup +}, Sr{sup +}, Ba{sup +}, Yb{sup +}, and Hg{sup +} are calculated by the multiconfiguration DiracHartreeFock and relativistic configurationinteraction methods. For Hg{sup +}, the configuration is 5d{sup 9}6s{sup 2}. For the other ions, the configuration consists of a single delectron outside a set of closed shells. Current interest in the quadrupole moments of these states is due to the fact that optical transitions of these ions may be useful as references for frequency standards. Energy shifts of the metastable states due to the interactions of the quadrupole moments with external electric field gradients are among the largest sources of error in these frequency standards. For the quadrupole moments, agreement is obtained to within about 10% with the available measurements. For the hyperfine constants, good agreement is obtained with measurements and with other calculations, except for the A factors of the {sup 2}D{sub 5/2} states of Sr{sup +}, Ba{sup +}, and Yb{sup +}, where the correlation effects are so large that they reverse the sign of the constant relative to the DiracHartreeFock value. As a test of the Hg{sup +} calculational methods, quadrupole moments and hyperfine constants are calculated for the 5d{sup 9}6s{sup 2} {sup 2}D{sub 3/2,5/2} states in isoelectronic neutral Au. This yields a value of the nuclear quadrupole moment Q({sup 197}Au)=+0.587(29) b.},
doi = {10.1103/PHYSREVA.73.022510},
journal = {Physical Review. A},
number = 2,
volume = 73,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2006},
month = {Wed Feb 15 00:00:00 EST 2006}
}

The narrow optical frequency resonances of the 6s {sup 2}S{sub 1/2}{yields}5d {sup 2}D{sub 3/2} and 6s {sup 2}S{sub 1/2}{yields}5d {sup 2}D{sub 5/2} forbidden transitions in Ba{sup +} have been proposed as suitable frequencies for a new optical frequency standard. The major sources of errors in measurements of singly ionized systems are due to the quadratic Zeeman and electric quadrupole shifts. We report here the most accurate calculations to date for the hyperfine structure constants and electricquadrupole moments of the 5d {sup 2}D{sub 3/2} and 5d {sup 2}D{sub 5/2} states in Ba{sup +}, which determine the quadratic Zeeman and electric quadrupolemore »

Atomic properties calculated by relativistic coupledcluster theory without truncation: Hyperfine constants of Mg{sup +}, Ca{sup +}, Sr{sup +}, and Ba{sup +}
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Lifetimes of the metastable {sup 2}D{sub 3/2,5/2} states in Ca{sup +}, Sr{sup +}, and Ba{sup +}
Atomic properties involving the lowlying excited {sup 2}D{sub 3/2,5/2} states in alkalineearthmetal ions are of current interest in many different applications ranging from tests of physics beyond the standard model to astrophysics. We have used the relativistic coupledcluster theory to perform accurate calculations of the lifetimes of the lowest excited {sup 2}D{sub 3/2} and {sup 2}D{sub 5/2} states in singly ionized calcium, strontium, and barium. The importance of electron correlation in these calculations is emphasized. Our results are compared with the available experimental and theoretical data.