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We show that Ramsey spectroscopy of fermionic alkaline-earth atoms in a square-well trap provides an efficient and accurate estimate for the eigenspectrum of a density matrix whose $n$ copies are stored in the nuclear spins of $n$ such…

We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn-Sham density-functional theory (DFT). To this end, we develop an…

Computational Physics · Physics 2015-06-05 Phani Motamarri , Michael R Nowak , Kenneth Leiter , Jaroslaw Knap , Vikram Gavini

We proposed in Ref. [arXiv:1812.09285v2] a way to improve energy density functionals in the density functional theory based on the combination of the inverse Kohn-Sham method and the density functional perturbation theory. In this…

Chemical Physics · Physics 2020-12-24 Tomoya Naito , Daisuke Ohashi , Haozhao Liang

We develop a spectrally accurate numerical method to compute solutions of a model partial differential equation used in plasma physics to describe diffusion in velocity space due to Fokker-Planck collisions. The solution is represented as a…

Classical Analysis and ODEs · Mathematics 2015-03-18 Jon Wilkening , Antoine Cerfon

In the distributed nucleus approximation we represent the singular nucleus as smeared over a smallportion of a Cartesian grid. Delocalizing the nucleus allows us to solve the Poisson equation for theoverall electrostatic potential using a…

chem-ph · Physics 2009-10-28 Karthik A. Iyer , Michael P. Merrick , Thomas L. Beck

We propose to expand the territory of density functional theory to strongly correlated electrons by reformulating the Kohn-Sham scheme in the representation of fractionalized particles. We call it the ``KS* scheme.'' Using inhomogeneous…

Computational Physics · Physics 2025-04-08 Bo Zhao , Jingyu Zhao , Zheng Zhu , Jian Wu , Zheng Liu

We develop a stochastic formulation of the optimally-tuned range-separated hybrid density functional theory which enables significant reduction of the computational effort and scaling of the non-local exchange operator at the price of…

Chemical Physics · Physics 2016-09-28 Daniel Neuhauser , Eran Rabani , Yael Cytter , Roi Baer

Efficient and stable algorithms for the calculation of spectral quantities and correlation functions are some of the key tools in computational condensed matter physics. In this article we review basic properties and recent developments of…

Other Condensed Matter · Physics 2007-05-23 Alexander Weisse , Gerhard Wellein , Andreas Alvermann , Holger Fehske

We present a spectral finite-element formulation of the optimized effective potential (OEP) method for atomic structure calculations in the random phase approximation (RPA). In particular, we develop a finite-element framework that employs…

Computational Physics · Physics 2026-01-28 Shubhang Krishnakant Trivedi , Phanish Suryanarayana

We integrate the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding (QM/MM) calculations. A major undertaking in this integration is the implementation of pseudopotential…

We present a fully pseudo-spectral scheme to solve axisymmetric hyperbolic equations of second order. With the Chebyshev polynomials as basis functions, the numerical grid is based on the Lobbato (for two spatial directions) and Radau (for…

Computational Physics · Physics 2016-07-28 Rodrigo P. Macedo , Marcus Ansorg

We present a framework for obtaining reliable solid-state charge and optical excitations and spectra from optimally-tuned range-separated hybrid density functional theory. The approach, which is fully couched within the formal framework of…

Materials Science · Physics 2015-09-30 Sivan Refaely-Abramson , Manish Jain , Sahar Sharifzadeh , Jeffrey B. Neaton , Leeor Kronik

We present a new theory for partitioning simulations of periodic and solid-state systems into physically sound atomic contributions at the level of Kohn-Sham density functional theory. Our theory is based on spatially localized linear…

Chemical Physics · Physics 2024-10-01 Luna Zamok , Janus J. Eriksen

Classical approximation bases such as Chebyshev polynomials provide principled and interpretable representations, but their multivariate tensor-product constructions scale exponentially with dimension and impose axis-aligned structure that…

Machine Learning · Computer Science 2026-04-07 Milo Coombs

In this paper, we investigate the energy minimization model of the ensemble Kohn-Sham density functional theory for metallic systems, in which a pseudo-eigenvalue matrix and a general smearing approach are involved. We study the invariance…

Numerical Analysis · Mathematics 2022-01-19 Xiaoying Dai , Stefano de Gironcoli , Bin Yang , Aihui Zhou

We present a method to discretize the Kohn-Sham Hamiltonian matrix in the pseudopotential framework by a small set of basis functions automatically contracted from a uniform basis set such as planewaves. Each basis function is localized…

Computational Physics · Physics 2015-06-03 Lin Lin , Lexing Ying

We show that deep neural networks can be integrated into, or fully replace, the Kohn-Sham density functional theory scheme for multi-electron systems in simple harmonic oscillator and random external potentials with no feature engineering.…

Materials Science · Physics 2021-02-25 Kevin Ryczko , David Strubbe , Isaac Tamblyn

We describe how to apply the recently developed pole expansion and selected inversion (PEXSI) technique to Kohn-Sham density function theory (DFT) electronic structure calculations that are based on atomic orbital discretization. We give…

Computational Physics · Physics 2015-06-04 Lin Lin , Mohan Chen , Chao Yang , Lixin He

The self consistent version of the density functional theory is presented, which allows to calculate the ground state and dynamic properties of finite multi-electron systems. An exact functional equation for the effective interaction, from…

Materials Science · Physics 2017-08-23 M. Ya. Amusia , A. Z. Msezane , V. R. Shaginyan

Static electric response properties of atoms and molecules are reported within the real-space Cartesian grid implementation of pseudopotential Kohn-Sham (KS) density functional theory (DFT). A detailed systematic investigation is made for a…

Chemical Physics · Physics 2019-04-26 Tanmay Mandal , Abhisek Ghosal , Amlan K. Roy