Calculating electron momentum densities and Compton profiles using the linear tetrahedron method

Ernsting, David; Billington, David P.; Haynes, T. D.; Millichamp, Tom; Taylor, Jonathan; Duffy, J. A.; Giblin, Sean; Dewhurst, J. K.; Dugdale, Stephen B

doi:10.1088/0953-8984/26/49/495501

Cited by 33 publications

(34 citation statements)

References 54 publications

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“…Since Pd has a relatively high atomic number, the spin-orbit interaction was included in the calculations by adding a term of the form σ • L (where σ is the spin vector and L is the orbital angular momentum vector) to the second variational Hamiltonian. Because the Compton scattering and 2D-ACAR experiments were performed at room temperature and at T = 10 K, respectively, smearing widths (effective electronic temperatures) of 300 K and 30 K were used in the ground-state calculations from which the EMD and TPMD, respectively, were calculated using the method of Ernsting et al [57]. Compton scattering is equally sensitive to all electrons (core and valence) and, while the EMD was calculated only for the valence electrons, the momentum cutoff was |p| max = 16.0 a.u.…”

Section: First-principles Electronic Structure Calculationmentioning

confidence: 99%

Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method

Ketels

Billington²,

Dugdale³

et al. 2021

Phys. Rev. B

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Two-dimensional (2D) angular correlation of annihilation radiation and Compton scattering are both powerful techniques to investigate the bulk electronic structure of crystalline solids through the momentum density of the electrons. Here we apply both methods to a single crystal of Pd to study the electron momentum density and the occupancy in the first Brillouin zone and to point out the complementary nature of the two techniques. To retrieve the 2D spectra from one-dimensional Compton profiles, a direct inversion method is implemented and benchmarked against the well-established Cormack's method. The comparison of experimental spectra with first-principles density functional theory calculations of the electron momentum density and the two photon momentum density clearly reveals the importance of positron probing effects on the determination of the electronic structure. While the calculations are in good agreement with the experimental data, our results highlight some significant discrepancies.

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Section: First-principles Electronic Structure Calculationmentioning

confidence: 99%

Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method

Ketels

Billington²,

Dugdale³

et al. 2021

Phys. Rev. B

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“…Spin-orbit coupling was included in the calculation by adding a term of the form σ · L , where σ is the spin vector and L is the orbital angular momentum vector, to the second variational Hamiltonian. The calculated electron momentum densities and Compton profiles were produced from the calculated electronic structure by the method of Ernsting et al 37 .…”

Section: Methodsmentioning

confidence: 99%

Magnetic frustration, short-range correlations and the role of the paramagnetic Fermi surface of PdCrO2

Billington

Ernsting

Millichamp

et al. 2015

Sci Rep

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Frustrated interactions exist throughout nature, with examples ranging from protein folding through to frustrated magnetic interactions. Whilst magnetic frustration is observed in numerous electrically insulating systems, in metals it is a rare phenomenon. The interplay of itinerant conduction electrons mediating interactions between localised magnetic moments with strong spin-orbit coupling is likely fundamental to these systems. Therefore, knowledge of the precise shape and topology of the Fermi surface is important in any explanation of the magnetic behaviour. PdCrO2, a frustrated metallic magnet, offers the opportunity to examine the relationship between magnetic frustration, short-range magnetic order and Fermi surface topology. By mapping the short-range order in reciprocal space and experimentally determining the electronic structure, we have identified the dual role played by the Cr electrons in which the itinerant ones on the nested paramagnetic Fermi surface mediate the frustrated magnetic interactions between local moments.

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“…It is also reassuring that the most reliable electron-positron LDA parametrization (based on the QMC simulations) combined with the parameter free gradient correction gives the best results compared with any of the older LDA potentials. Further studies combining the present approach with well-converged momentum densities calculations [50] are needed to check if first principle methods can soon improve the agreement over empirical approaches [42]. …”

mentioning

confidence: 99%

Proposed Parameter-Free Model for Interpreting the Measured Positron Annihilation Spectra of Materials Using a Generalized Gradient Approximation

Barbiellini

Kuriplach

2015

Phys. Rev. Lett.

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Positron annihilation spectroscopy is often used to analyze the local electronic structure of materials of technological interest. Reliable theoretical tools are crucial to interpret the measured spectra. Here, we propose a parameter-free gradient correction scheme for a local-density approximation obtained from high quality quantum Monte Carlo data. The results of our calculations compare favorably with positron affinity and lifetime measurements opening new avenues for highly precise and advanced positron characterization of materials.

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Calculating electron momentum densities and Compton profiles using the linear tetrahedron method

Cited by 33 publications

References 54 publications

Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method

Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method

Magnetic frustration, short-range correlations and the role of the paramagnetic Fermi surface of PdCrO2

Proposed Parameter-Free Model for Interpreting the Measured Positron Annihilation Spectra of Materials Using a Generalized Gradient Approximation

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