Many-body renormalization of forces in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>f</mml:mi></mml:math>
-electron materials

Plekhanov, Evgeny; Hasnip, Phil; Sacksteder, Vincent; Probert, Matt; Clark, S. J.; Refson, Keith; Weber, Cédric

doi:10.1103/physrevb.98.075129

Cited by 30 publications

(33 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this manuscript, we focused on the DMFT approach within the framework of fixed Kohn-Sham (KS) potentials, the so-called "one-shot" DFT+DMFT method. This has been shown to predict the equilibrium volume and bulk modulus for f materials that are in excellent agreement with experimental data 40 . We use typical values for the Coulomb repulsion (U = 6 eV) and Hund's coupling (J = 1 eV).…”

Section: Electronic Structure Calculationssupporting

confidence: 66%

“…Structural optimization of bulk Tb in the mC4 and oF 16 phases was accomplished by using spin-polarised DFT calculations with the help of the VASP 38 package using the PBE functional 39 . The many-body properties of the mC4 and oF 16 phases were further investigated by using a recent implementation of DFT+Dynamical Mean-Field Theory (DFT+DMFT) in the CASTEP code [40][41][42] . The k-point sampling was done using a Monkhorst-Pack mesh of 8×8×8 for the oF 16 and 10×10×6 for the mC4 structures, respectively, and a Gaussian smearing of 0.1 eV.…”

Section: Electronic Structure Calculationsmentioning

confidence: 99%

See 1 more Smart Citation

Structure and magnetism of collapsed lanthanide elements

et al. 2019

View full text Add to dashboard Cite

Using synchrotron X-ray diffraction, we show that the long-accepted monoclinic structure of the "collapsed" high-pressure phases reported in seven lanthanide elements (Nd, Tb, Gd, Dy, Ho, Er and (probably) Tm) is incorrect. In Tb, Gd, Dy, Ho, Er and Tm we show that the collapsed phases have a 16-atom orthorhombic structure (oF 16) not previously seen in the elements, while in Nd we show that it has an 8-atom orthorhombic structure (oF 8) previously reported in several actinide elements. oF 16 and oF 8 are members of a new family of layered elemental structures, the discovery of which reveals that the high-pressure structural systematics of the lanthanides, actinides and group 3 elements (Sc and Y) are much more related that previously imagined. Electronic structure calculations of Tb, combined with quantum many body corrections, confirm the experimental observation, and calculate that the collapsed orthorhombic phase is a ferromagnet, nearly degenerate with an anti-ferromagnetic state between 60 and 80 GPa. We find that the magnetic properties of Tb survive to the highest pressures obtained in our experiments (110 GPa). Further calculations of the collapsed phases of Gd and Dy, again using the correct crystal structure, show the former to be a type-A antiferromagnet, while the latter is ferromagnetic.

show abstract

Section: Electronic Structure Calculationssupporting

confidence: 66%

Section: Electronic Structure Calculationsmentioning

confidence: 99%

Structure and magnetism of collapsed lanthanide elements

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Double counting is not unambiguously resolved in DFT+DMFT, and there is no incontestable way to perform this correction. In CASTEP there is a choice of three double counting corrections: i) Fully localised limit (FLL); ii) Around mean-field limit, and iii) Held's correction [10] [38] [39], [15]. A selection can be made according to the modelling context.…”

Section: Discussionmentioning

confidence: 99%

Continuous-time quantum Monte Carlo solver for dynamical mean field theory in the compact Legendre representation

et al. 2019

Self Cite

View full text Add to dashboard Cite

Dynamical mean-field theory (DMFT) is one of the most widely-used methods to treat accurately electron correlation effects in ab-initio real material calculations. Many modern large-scale implementations of DMFT in electronic structure codes involve solving a quantum impurity model with a Continuous-Time Quantum Monte Carlo (CT-QMC) solver [1][2][3][4]. The main advantage of CT-QMC is that, unlike standard quantum Monte Carlo approaches, it is able to generate the local Green's functions G(τ ) of the correlated system on an arbitrarily fine imaginary time τ grid, and is free of any systematic errors. In this work, we extend a hybrid QMC solver proposed by Khatami et al. [5] and Rost et al.[6] to a multi-orbital context. This has the advantage of enabling impurity solver QMC calculations to scale linearly with inverse temperature, β, and permit its application to d and f band materials. In addition, we present a novel Green's function processing scheme which generates accurate quasi-continuous imaginary time solutions of the impurity problem which overcome errors inherent to standard QMC approaches. This solver and processing scheme are incorporated into a full DFT+DMFT calculation using the CASTEP DFT code [7]. Benchmark calculations for SrVO3 properties are presented.

show abstract

“…Inter-operability between Quantum Espresso (QE) [24,25] was accomplished through input file format conversion, pseudopotentials, and k-point grids. The many-body corrections were provided by core libraries via the DMFT quantum embedding, which resulted in corrected forces [22] and total free energies [26,27]. The underlying structure relaxations were carried out using the QE and CASTEP packages in the framework of DFT and using the Perdew-Burke-Ernzerhof generalised gradient approximation (PBE-GGA) [28,29].…”

Section: Methodsmentioning

confidence: 99%

High-Temperature Superconductivity in the Lanthanide Hydrides at Extreme Pressures

et al. 2022

Self Cite

View full text Add to dashboard Cite

Hydrogen-rich superhydrides are promising high-Tc superconductors, with superconductivity experimentally observed near room temperature, as shown in recently discovered lanthanide superhydrides at very high pressures, e.g., LaH10 at 170 GPa and CeH9 at 150 GPa. Superconductivity is believed to be closely related to the high vibrational modes of the bound hydrogen ions. Here, we studied the limit of extreme pressures (above 200 GPa) where lanthanide hydrides with large hydrogen content have been reported. We focused on LaH16 and CeH16, two prototype candidates for achieving a large electronic contribution from hydrogen in the electron–phonon coupling. In this work, we propose a first-principles calculation platform with the inclusion of many-body corrections to evaluate the detailed physical properties of the Ce–H and La–H systems and to understand the structure, stability, and superconductivity of these systems at ultra-high pressure. We provide a practical approach to further investigate conventional superconductivity in hydrogen-rich superhydrides. We report that density functional theory provides accurate structure and phonon frequencies, but many-body corrections lead to an increase of the critical temperature, which is associated with the spectral weight transfer of the f-states.

show abstract

Many-body renormalization of forces in f -electron materials

Cited by 30 publications

References 49 publications

Structure and magnetism of collapsed lanthanide elements

Structure and magnetism of collapsed lanthanide elements

Continuous-time quantum Monte Carlo solver for dynamical mean field theory in the compact Legendre representation

High-Temperature Superconductivity in the Lanthanide Hydrides at Extreme Pressures

Contact Info

Product

Resources

About