Role of spin in the calculation of Hubbard 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>U</mml:mi></mml:math>
 and Hund's 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>J</mml:mi></mml:math>
 parameters from first principles

Linscott, Edward; Cole, D. J. A.; Payne, Michael; O’Regan, David D.

doi:10.1103/physrevb.98.235157

Cited by 54 publications

(56 citation statements)

References 136 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The values of U lr eff virtually do not depend on the size of the unit cell in both cases with and without spin polarization. The limitation of the linear response method in accounting for the screening effect of the opposite spin channel of the same site was demonstrated in a recent paper 30 . This may be a reason why the linear response method applied in this study predicts U lr eff ~ 9.6 eV at pressures below 20 GPa.…”

Section: Resultsmentioning

confidence: 99%

First-principles calculations of the epsilon phase of solid oxygen

Wada

Fukui

Kawatsu

et al. 2019

Sci Rep

View full text Add to dashboard Cite

The crystal, electronic and magnetic structures of solid oxygen in the epsilon phase have been investigated using the strongly constrained appropriately normed (SCAN) + rVV10 method and the generalized gradient approximation (GGA) + vdW-D + U method. The spin-polarized SCAN + rVV10 method with an 8-atom primitive unit cell provides lattice parameters consistent with the experimental results over the entire pressure range, including the epsilon-zeta structural phase transition at high pressure, but does not provide accurate values of the intermolecular distances d 1 and d 2 at low pressure. The agreement between the intermolecular distances and the experimental values is greatly improved when a 16-atom conventional unit cell is used. Therefore, the SCAN + rVV10 method with a 16-atom unit cell can be considered the most suitable model for the epsilon phase of solid oxygen. The spin-polarized SCAN + rVV10 model predicts a magnetic phase at low pressure. Since the lattice parameters of the predicted magnetic structure are consistent with the experimental lattice parameters measured at room temperature, our results may suggest that the epsilon phase is magnetic even at room temperature. The GGA + vdW-D + U (with an ad hoc value of U eff = 2 eV at low pressure instead of the first-principles value of U lr eff ~ 9 eV) and hybrid functional methods provide similar results to the SCAN + rVV10 method; however, they do not provide reasonable values for the intermolecular distances.

show abstract

Section: Resultsmentioning

confidence: 99%

First-principles calculations of the epsilon phase of solid oxygen

Wada

Fukui

Kawatsu

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The larger values of U sc computed for LS compared to HS may derive from the overestimation of U sc for LS as already discussed in the literature. 38,69,70 Such an overestimation is here reflected by the overcorrection of the density produced by U sc in LS and is shown by the concave E dev in Figure 2. From the above observations, since the penalizing Hubbard term, EU, is proportional to the m,σ [n σ m (1 − n σ m )] and U , the larger bias towards HS predicted for strong-field ligands can be mitigated by adopting a value of U smaller than U sc.…”

Section: Hom O Q=1mentioning

confidence: 94%

Biased Spin-State Energetics of Fe(II) Molecular Complexes within Density-Functional Theory and the Linear-Response HubbardUCorrection

Mariano

Vlaisavljevich

Poloni

2020

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The spin-state energetics of six Fe(II) molecular complexes are computed using the linear-response Hubbard U approach within DFT. The adiabatic energy differences, ∆E H-L , between the high spin (S=2) and the low spin (S=0) states are computed and compared with accurate coupled clustercorrected CASPT2 results. We show that DFT+U fails in correctly capturing the ground state for strong field-ligands yielding ∆E H-L that are almost constant throughout the molecular series. This bias towards high spin together with the metal/ligand charge transfer upon U correction are here quantified and explained using molecular orbital diagrams involving both σ-and π-bonding interactions. With increasing ligandfield strengths this bias also increases owing to the stronger molecular character of the metal/ligand Kohn-Sham orbitals thus resulting in large deviations from the reference larger than 4 eV. Smaller values of U can be employed to mitigate this effect and recover the right energetics.

show abstract

“…The local density approximation (LDA) and generalized gradient (GGA) [4] functionals were developed to add exchangecorrelation (XC) contributions to the energy functional within the Kohn-Sham (KS) formalism [5]. However, numerous studies have shown that these XC corrections have an associated self-interaction error (SIE) [3,6,7]. This shortcoming can be explained by the difficulty in quantifying full correlation effects without solving the multi-body Schrödinger equation.…”

Section: Introductionmentioning

confidence: 99%

“…This simpler formalism arises if one assumes that the effective Coulombic exchange integrals (in terms of U and J) are symmetric between spin-up and spin-down electrons [3]. The Dudarev +U functional has drawbacks in the case of magnetic, or highly spin-polarized, systems in which case this approximation fails to capture the spin-dependent nature of the on-site exchange interaction due to a breaking of time-reversal symmetry [7].…”

Section: Introductionmentioning

confidence: 99%

High-throughput determination of Hubbard U and Hund J values for transition metal oxides via linear response formalism

Moore¹,

Horton²,

Ganose³

et al. 2022

Preprint

View full text Add to dashboard Cite

Hubbard U and Hund J values provide a measure of the self-interaction between correlated electrons, and are crucial parameters in the formalism of density functional theory with a "plus U " correction, known as DFT+U and DFT+U +J. The linear response (LR) methodology has proven to be a computationally effective and self-contained method for computing accurate U and J values. This study provides a high-throughput computational analysis of the U and J values applied to transition metal d-electron states in a representative set of magnetic transition metal oxides (TMOs). In a less conventional pursuit, over two hundred system-specific U and J corrections are calculated for oxygen 2p on-site occupations. The distributions of values are analyzed for structures containing manganese, iron and nickel-containing compounds, with sample sizes of over 150 for each species. In addition, periodic tables of U and J values are presented for transition metal and oxygen species from a combined data set of over 800 TMO compounds. Our work provides a frame of reference for researchers who utilize DFT+U to study TMO materials, and to gain insight into the distribution of U values that may be relevant to their applications. An atomate workflow is presented for calculating U and J values automatically on massively parallel supercomputing architectures. To validate this method, the spin-canting magnetic structure and unit cell parameters of a known multiferroic, olivine LiNiPO4, are predicted using the computed Hubbard U and Hund J values for Ni-d and O-p on-site occupancies, and are compared with experiment. It was confirmed that in addition to Ni-d U values, applying a separate Hund J to Ni-d has a strong effect on Ni-moment canting angle. Additionally, including a O-p U value results in a significantly improved agreement between DFT-computed lattice parameters and experiment.

show abstract

Role of spin in the calculation of Hubbard U and Hund's J parameters from first principles

Cited by 54 publications

References 136 publications

First-principles calculations of the epsilon phase of solid oxygen

First-principles calculations of the epsilon phase of solid oxygen

Biased Spin-State Energetics of Fe(II) Molecular Complexes within Density-Functional Theory and the Linear-Response HubbardUCorrection

High-throughput determination of Hubbard U and Hund J values for transition metal oxides via linear response formalism

Contact Info

Product

Resources

About