Application and Interpretation of Isomer Shifts

Shirley, D. A.

doi:10.1103/revmodphys.36.339

Cited by 315 publications

(101 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When an atomic nucleus undergoes a ␥ transition, the size of the nucleus, as characterized by its charge radius and matter radius, changes and this leads to slightly different electron-nuclear interaction energies in the ground and in the excited states of the nucleus [40]. This energy difference is thus dependent on the local electronic structure.…”

Section: Introductionmentioning

confidence: 99%

“…Magnitude of the isomer shift is determined simultaneously by characteristics of the nuclear structure, such as the charge radius variation during the ␥ transition, and of the local electronic structure, such as the electron density in the vicinity of nucleus [6,40]. Although, in principle, both characteristics are physical observables, none of them is accessible via direct experimental measurements.…”

Section: Introductionmentioning

confidence: 99%

“…The Mössbauer isomer shift ␦ arises from the electrostatic interaction between nuclear and electron charge distributions due to the finite size of the nucleus [6,40,[37][38][39]. When an atomic nucleus undergoes a ␥ transition, the size of the nucleus, as characterized by its charge radius and matter radius, changes and this leads to slightly different electron-nuclear interaction energies in the ground and in the excited states of the nucleus [40].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

First principles calculation of Mössbauer isomer shift

Filatov

2009

Coordination Chemistry Reviews

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

First principles calculation of Mössbauer isomer shift

Filatov

2009

Coordination Chemistry Reviews

View full text Add to dashboard Cite

“…In the traditional approach [45][46][47], the energy shift associated with going from a point nucleus to a nucleus of finite size is expressed in terms of perturbation theory and evaluated separately for the ground and excited nuclear state. This is hardly a viable approach in a relativistic framework due to the weak singularity of the electron density at the nucleus.…”

Section: Validity Of the Contact Density Approximationmentioning

confidence: 99%

Mössbauer spectroscopy for heavy elements: a relativistic benchmark study of mercury

Knecht

Fux

Meer³

et al. 2011

Theor Chem Acc

View full text Add to dashboard Cite

The electrostatic contribution to the Mössbauer isomer shift of mercury for the series HgF n (n = 1, 2, 4) with respect to the neutral atom has been investigated in the framework of four-and two-component relativistic theory. Replacing the integration of the electron density over the nuclear volume by the contact density (that is, the electron density at the nucleus) leads to a 10% overestimation of the isomer shift. The systematic nature of this error suggests that it can be incorporated into a correction factor, thus justifying the use of the contact density for the calculation of the Mössbauer isomer shift. The performance of a large selection of density functionals for the calculation of contact densities has been assessed by comparing with finite-field four-component relativistic coupled-cluster with single and double and perturbative triple excitations [CCSD(T)] calculations. For the absolute contact density of the mercury atom, the Density Functional Theory (DFT) calculations are in error by about 0.5%, a result that must be judged against the observation that the change in contact density along the series HgF n (n = 1, 2, 4), relevant for the isomer shift, is on the order of 50 ppm with respect to absolute densities. Contrary to previous studies of the 57 Fe isomer shift (F Neese, Inorg Chim Acta 332:181, 2002), for mercury, DFT is not able to reproduce the trends in the isomer shift provided by reference data, in our case CCSD(T) calculations, notably the non-monotonous decrease in the contact density along the series HgF n (n = 1, 2, 4). Projection analysis shows the expected reduction of the 6s 1/2 population at the mercury center with an increasing number of ligands, but also brings into light an opposing effect, namely the increasing polarization of the 6s 1/2 orbital due to increasing effective charge of the mercury atom, which explains the nonmonotonous behavior of the contact density along the series. The same analysis shows increasing covalent contributions to bonding along the series with the effective charge of the mercury atom reaching a maximum of around ?2 for HgF 4 at the DFT level, far from the formal charge ?4 suggested by the oxidation state of this recently observed species. Whereas the geometries for the linear HgF 2 and square-planar HgF 4 molecules were taken from previous computational studies, we optimized the equilibrium distance of HgF at the four-component Fock-space CCSD/aug-cc-pVQZ level, giving spectroscopic constants r e = 2.007 Å and x e = 513.5 cm -1 .Dedicated to Professor Pekka Pyykkö on the occasion of his 70th birthday and published as part of the Pyykkö Festschrift Issue.Electronic supplementary material The online version of this article

show abstract

“…2,3,9 This equation is most straightforwardly derived within the nonrelativistic formalism. Within this formalism, the electron density remains finite in the vicinity of a point-charge nucleus.…”

Section: Introductionmentioning

confidence: 99%

DFT Approach to the Calculation of Mössbauer Isomer Shifts

Kurian

Filatov

2008

J. Chem. Theory Comput.

View full text Add to dashboard Cite

With the help of a recently suggested computational scheme [J. Chem. Phys. 2007, 127, 084101], Mössbauer isomer shifts are calculated within the context of density functional theory, for a series of iron containing compounds. The influence of the choice of a density functional and of the truncation of a basis set on the results of calculations is analyzed. It has been observed that the hybrid density functionals, especially BH&HLYP, provide better correlation with experimental results than pure density functionals. The analysis of basis set truncation reveals that the addition (or removal) of the tightmost primitive functions to a large uncontracted basis set has only a minor influence on the calculated isomer shift values. It is observed that, with the use of a small contracted basis set, a reasonable accuracy for the calculated isomer shifts can be achieved.

show abstract

Application and Interpretation of Isomer Shifts

Cited by 315 publications

References 32 publications

First principles calculation of Mössbauer isomer shift

First principles calculation of Mössbauer isomer shift

Mössbauer spectroscopy for heavy elements: a relativistic benchmark study of mercury

DFT Approach to the Calculation of Mössbauer Isomer Shifts

Contact Info

Product

Resources

About