Functional theory
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Understanding band gaps of solids in generalized Kohn–Sham theory Open
Significance Semiconductors and insulators have a fundamental energy gap and absorb light at a continuum of photon energies above this gap. They also have a band structure of one-electron energies, and a band gap separating unoccupied from…
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Pushing the frontiers of density functionals by solving the fractional electron problem Open
Improving DFT with deep learning In the past 30 years, density functional theory (DFT) has emerged as the most widely used electronic structure method to predict the properties of various systems in chemistry, biology, and materials scienc…
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Exact Double Counting in Combining the Dynamical Mean Field Theory and the Density Functional Theory Open
We propose a continuum representation of the dynamical mean field theory, in which we were able to derive an exact overlap between the dynamical mean field theory and band structure methods, such as the density functional theory; double co…
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Functional analysis of problem behavior: A 40‐year review Open
Extensive reviews of functional analysis literature were conducted 10 (Beavers et al., 2013) and 20 (Hanley et al., 2003) years ago; we expanded this review to capture the vast and innovative functional analysis research that has occurred …
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Machine Learning the Physical Nonlocal Exchange–Correlation Functional of Density-Functional Theory Open
We train a neural network as the universal exchange-correlation functional of density-functional theory that simultaneously reproduces both the exact exchange-correlation energy and the potential. This functional is extremely nonlocal but …
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Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters Open
Excited-state descriptors based on the one-particle transition density matrix referring to the exciton picture have been implemented for time-dependent density functional theory. State characters such as local, extended ππ∗, Rydberg, or ch…
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DeePKS: A Comprehensive Data-Driven Approach toward Chemically Accurate Density Functional Theory Open
We propose a general machine learning-based framework for building an accurate and widely applicable energy functional within the framework of generalized Kohn-Sham density functional theory. To this end, we develop a way of training self-…
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Describing strong correlation with fractional-spin correction in density functional theory Open
Significance The static correlation error inherent in commonly used density functional approximations (DFAs) has seriously hindered the application of density functional theory (DFT) to strongly correlated systems. Here, an effective fract…
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First-principles determination of defect energy levels through hybrid density functionals and<i>GW</i> Open
In this topical review, we discuss recent progress in electronic-structure methods for calculating defect energy levels in semiconductors and insulators. We concentrate mainly on two advanced electronic-structure schemes, namely hybrid den…
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Double hybrids and time‐dependent density functional theory: An implementation and benchmark on charge transfer excited states Open
In this paper we present the implementation and benchmarking of a Time Dependent Density Functional Theory approach in conjunction with Double Hybrid (DH) functionals. We focused on the analysis of their performance for through space charg…
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Double and Charge-Transfer Excitations in Time-Dependent Density Functional Theory Open
Time-dependent density functional theory has emerged as a method of choice for calculations of spectra and response properties in physics, chemistry, and biology, with its system-size scaling enabling computations on systems much larger th…
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Computing the self-consistent field in Kohn-Sham density functional theory. Open
A new framework is presented for evaluating the performance of self-consistent field methods in Kohn-Sham density functional theory (DFT). The aims of this work are two-fold. First, we explore the properties of Kohn-Sham DFT as it pertains…
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Machine learning density functional theory for the Hubbard model Open
The solution of complex many-body lattice models can often be found by\ndefining an energy functional of the relevant density of the problem. For\ninstance, in the case of the Hubbard model the spin-resolved site occupation is\nenough to d…
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Spin-state energetics of metallocenes: How do best wave function and density functional theory results compare with the experimental data? Open
Benchmarking quantum-chemical methods against experiment-derived spin-state energetics of metallocenes.
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Self-consistent determination of the fictitious temperature in thermally-assisted-occupation density functional theory Open
We propose a self-consistent scheme for the determination of the fictitious temperature in thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai,J. Chem. Phys., 2012,136, 154104].
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Effects of Pore Parameters and Functional Groups in Coal on CO<sub>2</sub>/CH<sub>4</sub> Adsorption Open
The mechanisms of CO2/CH4 adsorption in coal are the theoretical foundation for CO2 sequestration in coal seams targeted for enhanced coalbed methane recovery. Herein, by changing the model (low rank coal: WMC, middle rank coal: XM and hig…
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Deep-Learning Density Functional Perturbation Theory Open
Calculating perturbation response properties of materials from first principles provides a vital link between theory and experiment, but is bottlenecked by the high computational cost. Here, a general framework is proposed to perform densi…
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Source-Free Exchange-Correlation Magnetic Fields in Density Functional Theory Open
Spin-dependent exchange-correlation energy functionals in use today depend on the charge density and the magnetization density: Exc[ρ, m]. However, it is also correct to define the functional in terms of the curl of m for physical external…
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Multiresolution quantum chemistry in multiwavelet bases: excited states from time-dependent Hartree–Fock and density functional theory via linear response Open
A fully numerical method for the time-dependent Hartree–Fock and density functional theory (TD-HF/DFT) with the Tamm–Dancoff (TD) approximation is presented in a multiresolution analysis (MRA) approach.
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Reduced density-matrix functionals from many-particle theory Open
\nIn materials with strong electron correlation the proper treatment of local atomic physics described by orbital occupations is crucial. Reduced density-matrix functional theory is a natural extension of density functional theory for syst…
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Machine learning the derivative discontinuity of density-functional theory Open
Machine learning is a powerful tool to design accurate, highly non-local, exchange-correlation functionals for density functional theory. So far, most of those machine learned functionals are trained for systems with an integer number of p…
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<i>Ab initio</i>theory of superconductivity in a magnetic field. I. Spin density functional theory for superconductors and Eliashberg equations Open
We present a first-principles approach to describe magnetic and\nsuperconducting systems and the phenomena of competition between these\nelectronic effects. We develop a density functional theory: SpinSCDFT, by\nextending the Hohenberg-Koh…
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Assessing the performance of approximate density functional theory on 95 experimentally characterized Fe(II) spin crossover complexes Open
Spin crossover (SCO) complexes, which exhibit changes in spin state in response to external stimuli, have applications in molecular electronics and are challenging materials for computational design. We curate a dataset of 95 Fe(II) SCO co…
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Optimal transport with Coulomb cost and the semiclassical limit of density functional theory Open
We present some progress in the direction of determining the semiclassical limit of the Levy-Lieb or Hohenberg-Kohn universal functional in density functional theory for Coulomb systems. In particular we give a proof of the fact that for B…
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Recent advances in ensemble density functional theory and linear response theory for strong correlation Open
The formulations and performances of spin ‐ restricted ensemble ‐ referenced KS and mixed‐reference spin‐flip time‐dependent density functional theory incorporating strong correlations into density functional theories are documented. As a …
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Fundamental Role of Fock Exchange in Relativistic Density Functional Theory Open
We perform a formal analysis of relativistic density functional theory for the treatment of spin-orbit coupling (SOC), noncollinear magnetization (NCM), and orbital current density (OCD). We identify specific components of the spinors (nam…
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Optical Activity of Spin‐Forbidden Electronic Transitions in Metal Complexes from Time‐Dependent Density Functional Theory with Spin‐Orbit Coupling Open
The calculation of magnetic transition dipole moments and rotatory strengths was implemented at the zeroth‐order regular approximation (ZORA) two‐component relativistic time‐dependent density functional theory (TDDFT) level. The circular d…
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Noncollinear density functional theory Open
An approach to generalize any kind of collinear functional in density functional theory to noncollinear functionals is proposed. This approach satisfies the correct collinear limit for any kind of functional, guaranteeing that the exact co…
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Accurate optical spectra of solids from pure time-dependent density functional theory Open
We present accurate optical spectra of semiconductors and insulators within a\npure Kohn-Sham time-dependent density-functional approach. In particular, we\nshow that the onset of the absorption is well reproduced when comparing to\nexperi…
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Unity of Kohn-Sham density-functional theory and reduced-density-matrix-functional theory Open
This work presents a theory to unify the two independent theoretical\nframeworks of Kohn-Sham (KS) density functional theory (DFT) and reduced\ndensity matrix functional theory (RDMFT). The generalization of the KS orbitals\nto hypercomple…