Computation of Mössbauer isomer shifts from first principles

Zwanziger, Josef W.

doi:10.1088/0953-8984/21/19/195501

Cited by 15 publications

(28 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Total contact densities also match well (e.g., DHF, 188,242 e -/a 0 3 ; DFT-PAW, ∼188,000 e -/a 0 3 for Sn 4+ ). Tests with point-nucleus DFT-PAW models show much more variable contact densities (∼1.6 × DHF) and much higher absolute contact densities (>400,000 e -/a 0 3 ) (28). DHF model contact densities increase by less than 2% if a much larger "quadruple-ζ" basis set is used.…”

Section: Methodsmentioning

confidence: 98%

“…The mean-squared radius difference found in ref. 28, 0.0048 fm 2 , is smaller mainly because of the use of point-nucleus PAW datasets. Using the calculated sensitivities in Table 2, energy shifts and 124 Sn/ 116 Sn fractionation factors have been estimated for a suite of tin sulfide crystals.…”

Section: Methodsmentioning

confidence: 99%

“…Projector augmented waves (26,27) enable efficient plane wave calculations in the space between atoms while also preserving information about the inner portion of atomic electronic structures. These favorable properties have previously been harnessed for a variety of modeling applications, including studies of Mössbauer isomer shifts (28) that influenced the design of the present work. Mössbauer isomer shifts and nuclear volume isotope effects have the same dependence on electron density at the nuclei of interest [varying in proportion to changes in ΔjΨ(0)j 2 ], so the apparent success of DFT-PAW in Mössbauer studies is encouraging.…”

mentioning

confidence: 99%

“…Tin is also the heaviest element in a recent DFT-PAW Möss-bauer calibration study (28) and has been the focus of other calibration studies (e.g., refs. 32 and 33).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Modeling nuclear volume isotope effects in crystals

Schauble

2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic DiracHartree-Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor-crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg 2 Cl 2 ), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium massindependent fractionations for several tin-bearing crystals are calculated from 119 Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium.Mössbauer spectroscopy | nuclear field shift | mass independent fractionation A mong the various causes of mass-independent isotope fractionation discovered over the past 40 years, the nuclear field shift effect (1) is unique in that it is an equilibrium thermodynamic phenomenon (and may also impart an identifiable and distinct signature in disequilibrium conditions) (2, 3). It has also proven amenable to prediction by electronic structure methods, at least in simple molecular systems (e.g., refs. 4-7). The goal of the present study is to extend the scope of systems that can be modeled to include condensed phases and crystals, and to speed up calculations for complex materials while retaining enough accuracy to be useful.Nuclear field shift effects result from the finite volume and sometimes nonspherical shapes of atomic nuclei, which are slightly different from one isotope to another. These differences in size and shape affect the coulomb potential felt by bound electrons, and thus the electronic structures of atoms and molecules. Nuclear field shifts have lo...

show abstract

Section: Methodsmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

“…Tin is also the heaviest element in a recent DFT-PAW Möss-bauer calibration study (28) and has been the focus of other calibration studies (e.g., refs. 32 and 33).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Modeling nuclear volume isotope effects in crystals

Schauble

2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…There remains the question of whether even all-electron accuracy in the valence space is sufficient for accurate representation of observables close to the nuclei, where conventional wisdom would suggest that deep core polarizations might be quite significant for properties such as the electric field gradient or Fermi contact interaction. Such concerns turn out to be unwarranted, however, as our experience and others have shown that the PAW formalism together with a typical chemical valence/core separation are sufficient for accurate description of nuclear point properties such as the electric field gradient [54][55][56], Fermi contact interaction [57] and magnetic chemical shielding [58].…”

Section: Properties At the Nuclei: Electric Field Gradients And Mössbmentioning

confidence: 99%

ABINIT: First-principles approach to material and nanosystem properties

Gonze

Amadon

Anglade

et al. 2009

Computer Physics Communications

2,476

1,603

View full text Add to dashboard Cite

Dispersion-Corrected Relativistic Density Functional Theory (DFT) Calculations of Structure and ¹¹⁹Sn Mössbauer Parameters for M≡SnR Bonding in Filippou’s Stannylidyne Complexes of Molybdenum and Tungsten

Pandey

2015

Inorg. Chem.

View full text Add to dashboard Cite

(119)Sn Mössbauer isomer shift (IS) and quadrupole splitting (ΔEQ) for M≡SnR bonding in metal-stannylidyne complexes trans-[Cl(PMe3)4Mo≡Sn-R] (1), trans-[Cl(PMe3)4W≡Sn-R] (2), trans-[Cl(dppe)2Mo≡Sn-R] (3), trans-[Cl(dppe)2W≡Sn-R] (4), [(dppe)2Mo≡Sn-R](+) (5), [(dppe)2W≡Sn-R](+) (6) (R = C6H3-2,6-Mes2) have been investigated for the first time. Calculations of optimized structures and (119)Sn Mössbauer parameters were carried out at the DFT/TPSS-D3(BJ)/TZVPP/ZORA level of theory. The calculated geometry parameters of stannylidyne complexes of molybdenum and tungsten (1-6) are in good agreement with experimental values of W-Sn and Sn-C bond distances. The calculated values of the isomer shift for the complexes (1-6) are almost same to the experimental values (within ±0.1 mm/s). Experimental values (ISexptl, 2.38-2.50 mm/s) and calculated values (IScalcd, 2.37-2.49 mm/s) of isomer shifts indicate that the oxidation state of tin in the studied complexes with M≡Sn-R bonding is Sn(II). The variations of ISexptl, as a function of Sn s electrons (Ns(Sn)), also exhibit a linear trend. (IS = 0.477Ns(Sn) - 1.888, R(2) = 0.9973). Calculated values of isomer shift (IScalcd) using the linear regression with the Ns(Sn) electron density are in excellent concord with the ISexptl.The calculated values of nuclear quadrupole splitting parameters (ΔEQ(calcd)) of (119)Sn using the relation ΔEQ(calcd) = (0.540 + 0.28) V are in agreement with the experimental values.

show abstract

Computation of Mössbauer isomer shifts from first principles

Cited by 15 publications

References 37 publications

Modeling nuclear volume isotope effects in crystals

Modeling nuclear volume isotope effects in crystals

ABINIT: First-principles approach to material and nanosystem properties

Dispersion-Corrected Relativistic Density Functional Theory (DFT) Calculations of Structure and ¹¹⁹Sn Mössbauer Parameters for M≡SnR Bonding in Filippou’s Stannylidyne Complexes of Molybdenum and Tungsten

Contact Info

Product

Resources

About

Computation of Mössbauer isomer shifts from first principles

Cited by 15 publications

References 37 publications

Modeling nuclear volume isotope effects in crystals

Modeling nuclear volume isotope effects in crystals

ABINIT: First-principles approach to material and nanosystem properties

Dispersion-Corrected Relativistic Density Functional Theory (DFT) Calculations of Structure and 119Sn Mössbauer Parameters for M≡SnR Bonding in Filippou’s Stannylidyne Complexes of Molybdenum and Tungsten

Contact Info

Product

Resources

About

Dispersion-Corrected Relativistic Density Functional Theory (DFT) Calculations of Structure and ¹¹⁹Sn Mössbauer Parameters for M≡SnR Bonding in Filippou’s Stannylidyne Complexes of Molybdenum and Tungsten