A5065000056- Advanced Chemical Physics Studies
- Machine Learning in Materials Science
- Spectroscopy and Quantum Chemical Studies
- Molecular Junctions and Nanostructures
- Computational Drug Discovery Methods
- Advanced NMR Techniques and Applications
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Surface and Thin Film Phenomena
- X-ray Diffraction in Crystallography
- Catalysis and Oxidation Reactions
- Superconductivity in MgB2 and Alloys
- Thermodynamic and Structural Properties of Metals and Alloys
- Quantum, superfluid, helium dynamics
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- Heusler alloys: electronic and magnetic properties
- Numerical methods in engineering
- nanoparticles nucleation surface interactions
- Boron and Carbon Nanomaterials Research
- Organic and Molecular Conductors Research
- Atmospheric Ozone and Climate
- Advanced Multi-Objective Optimization Algorithms
- NMR spectroscopy and applications
- Photochemistry and Electron Transfer Studies
Lawrence Berkeley National Laboratory
2023-2025
Temple University
2017-2023
Temple College
2020-2022
Tulane University
2020
University of California, Irvine
2020
The recently proposed rSCAN functional [ J. Chem. Phys. 2019 150, 161101] is a regularized form of the SCAN Rev. Lett. 2015 115, 036402] that improves SCAN's numerical performance at expense breaking constraints known from exact exchange-correlation functional. We construct new meta-generalized gradient approximation by restoring constraint adherence to rSCAN. resulting maintains rSCAN's while transferable accuracy SCAN.
We combine a regularized variant of the strongly constrained and appropriately normed semilocal density functional [J. Sun, A. Ruzsinszky, J. P. Perdew, Phys. Rev. Lett. 115, 036402 (2015)] with latest generation semi-classical London dispersion correction. The resulting approximation r2SCAN-D4 has speed generalized gradient approximations while approaching accuracy hybrid functionals for general chemical applications. demonstrate its numerical robustness in real-life settings benchmark...
Machine-learned force fields have transformed the atomistic modelling of materials by enabling simulations ab initio quality on unprecedented time and length scales. However, they are currently limited by: (i) significant computational human effort that must go into development validation potentials for each particular system interest; (ii) a general lack transferability from one chemical to next. Here, using state-of-the-art MACE architecture we introduce single general-purpose ML model,...
Strong correlations within a symmetry-unbroken ground-state wavefunction can show up in approximate density functional theory as symmetry-broken spin-densities or total densities, which are sometimes observable. They arise from soft modes of fluctuations (sometimes collective excitations) such spin-density charge-density waves at non-zero wavevector. In this sense, an for exchange and correlation that breaks symmetry be more revealing (albeit less accurate) than exact does not. The examples...
The recently proposed rSCAN functional [J. Chem. Phys. 150, 161101 (2019)] is a regularized form of the SCAN [Phys. Rev. Lett. 115, 036402 (2015)] that improves SCAN's numerical performance at expense breaking constraints known from exact exchange-correlation functional. We construct new meta-generalized gradient approximation by restoring constraint adherence to rSCAN. resulting maintains rSCAN's while transferable accuracy SCAN.
SCAN+rVV10 has been demonstrated to be a versatile van der Waals (vdW) density functional that delivers good predictions of both energetic and structural properties for many types bonding. Recently, the r$^{2}$SCAN devised as revised form SCAN with improved numerical stability. In this work, we refit rVV10 optimize r$^{2}$SCAN+rVV10 vdW functional, test its performance molecular interactions layered materials. Our tests demonstrate outperforms predecessor in efficiency (numerical stability)...
Delocalization errors, such as charge-transfer and some self-interaction plague computationally efficient otherwise accurate density functional approximations (DFAs). Evaluating a semilocal DFA non-self-consistently on the Hartree-Fock (HF) is often recommended inexpensive remedy for delocalization errors. For sophisticated meta-GGAs like SCAN, this approach can achieve remarkable accuracy. This HF-DFT (also known DFA@HF) presumed to work, when it significantly improves over DFA, because HF...
Energy barriers, which control the rates of chemical reactions, are seriously underestimated by computationally efficient semilocal approximations for exchange-correlation energy. The accuracy a density functional approximation is strongly boosted reaction barrier heights evaluating that non-self-consistently on Hartree-Fock electron densities, has been known ∼30 years. conventional explanation theory yields more accurate density. This work presents benchmark Kohn-Sham inversion...
High-throughput density functional theory (DFT) calculations have become a vital element of computational materials science, enabling screening, property database generation, and training “universal” machine learning models. While several software frameworks emerged to support these efforts, new developments such as learned force fields increased demands for more flexible programmable workflow solutions. This manuscript introduces atomate2, comprehensive evolution our original atomate...
A central aim of materials discovery is an accurate and numerically reliable description thermodynamic properties, such as the enthalpies formation decomposition. The r2SCAN revision strongly constrained appropriately normed (SCAN) meta-generalized gradient approximation (meta-GGA) balances numerical stability with high general accuracy. To assess solid-state thermodynamics, we evaluate decomposition enthalpies, equilibrium volumes, fundamental band gaps more than 1000 solids using r2SCAN,...
Density functional approximations to the exchange–correlation energy can often identify strongly correlated systems and estimate their energetics through energy-minimizing symmetry-breaking. In particular, binding curve of chromium dimer is described qualitatively by local spin density approximation (LSDA) almost quantitatively Perdew–Burke–Ernzerhof generalized gradient (PBE-GGA), where symmetry breaking antiferromagnetic for both. Here, we show that a full Perdew–Zunger...
The strongly constrained and appropriately normed (SCAN) meta-GGA exchange-correlation functional [Sun et al., Phys. Rev. Lett. 115, 036402 (2015)] is constructed as a chemical environment-determined interpolation between two separate energy densities: one describes single-orbital electron densities accurately another slowly varying accurately. To conserve constraints known for the exact functional, derivatives of this vanish in limit. While theoretically convenient, choice introduces...
Modern meta-GGAs based on the local kinetic energy density can predict properties of diverse systems with near experimental accuracy, but unexpectedly describe metallic solids poorly due to their underestimation screening in metals. In this work, authors replace dependence a sophisticated meta-GGA an approximation electronic gradient and Laplacian. This Laplacian-level is tested set solid-state properties: geometries, cohesive energies, bulk moduli, ferromagnetic moments, monovacancy...
Bolstered by recent calculations of exact functional-driven errors (FEs) and density-driven (DEs) semilocal density functionals in the water dimer binding energy [Kanungo, B. J. Phys. Chem. Lett. 2024, 15, 323–328], we investigate approximate FEs DEs neutral clusters containing up to 20 monomers, charged clusters, alkali- halide-water clusters. Our proxy for is r2SCAN 50, a 50% global hybrid exchange with r2SCAN, which may be less correct than compact monomer but importantly more long-range...
The SCAN (strongly constrained and appropriately normed) meta-generalized gradient approximation (meta-GGA), which satisfies all 17 exact constraints that a meta-GGA can satisfy, accurately describes equilibrium bonds are normally correlated. With symmetry breaking, it also some sd strongly While sp nearly always correlated, the C2 singlet ground state is known from correlated wave function theory to be rare case of strong correlation in an bond. Earlier work calculated atomization energies...
Transition metal oxide materials are of great utility, with a diversity topical applications ranging from catalysis to electronic devices. Because their widespread importance in science, there is increasing interest developing computational tools capable reliable prediction transition phase behavior and properties. The workhorse theory density functional (DFT). Accordingly, we have investigated the impact various correlation exchange approximations on ability predict properties NiO using...
We propose a spatially and temporally nonlocal exchange correlation (XC) kernel for the spin-unpolarized fluid phase of ground-state jellium use in time-dependent density functional linear response calculations. The is constructed to satisfy known properties exact XC accurately describe energies bulk frequency-moment sum rules at wide range densities, including those low densities that display strong symmetry breaking. These effects are easier understand simple model than real systems. All...
CoeffNet uses coefficients of molecular orbitals reactants and products to predict activation barriers.
Exact density functionals for the exchange and correlation energies are approximated in practical calculations ground-state electronic structure of a many-electron system. An important exact constraint construction approximations is to recover correct non-relativistic large-Z expansions corresponding neutral atoms with atomic number Z electron N = Z, which leading order (-0.221Z5/3 -0.021Z ln respectively) even lowest-rung or local approximation. We find that hydrogenic densities lead Ex(N,...
Under pressure, a quasi-two-dimensional electron gas can collapse toward the true two-dimensional (2D) limit. In this limit, exact exchange-correlation energy per has known finite but general-purpose semilocal approximate density functionals, such as local approximation (LDA) and Perdew-Burke-Ernzerhof generalized gradient (PBE GGA), are to diverge minus infinity. Here we consider model for noninteracting confined thickness $L$ by infinite-barrier walls, with fixed 2D...
Analytic mathematical models for the static spin ($G_-$) and density ($G_+$) local field factors uniform electron gas (UEG) as functions of wavevector are presented. These closely fit recent quantum Monte Carlo (QMC) data satisfy exact asymptotic limits. This model $G_-$ is available first time, present $G_+$ an improvement over previous work. The QMC-computed $G_\pm$ consistent with a rapid crossover between theoretically-derived small-$q$ large-$q$ expansions $G_\pm$. completely determined...
Bolstered by recent calculations of exact functional-driven errors (FEs) and density-driven (DEs) semi-local density functionals in the water dimer binding energy [Kanungo et al., J. Phys. Chem. Lett. 2023, 15, 323], we investigate approximate FEs DEs neutral clusters containing up to 20 monomers, charged clusters, alkali- halide-water clusters. Our proxy for is r2SCAN50, a 50% global hybrid exchange with r2SCAN, which may be less correct than r2SCAN compact monomer but importantly more...
Abstract Classical turning surfaces of Kohn–Sham potentials separate classically allowed regions (CARs) from forbidden (CFRs). They are useful for understanding many chemical properties molecules but need not exist in solids, where the density never decays to zero. At equilibrium geometries, we find that CFRs absent perfect metals, rare covalent semiconductors at equilibrium, common ionic and molecular crystals. In all materials, appear or grow as internuclear distances uniformly expanded....