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Related papers: Dynamical Kernels for Optical Excitations

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A new parameter-free approximation for the exchange-correlation kernel $f_{\rm xc}$ of time-dependent density functional theory is proposed. This kernel is expressed as an algorithm in which the exact Dyson equation for the response as well…

Materials Science · Physics 2015-05-28 S. Sharma , J. K. Dewhurst , A. Sanna , E. K. U. Gross

First-principles dynamical CPA (Coherent-Potential Approximation) for electron correlations has been developed further by taking into account higher-order dynamical corrections with use of the asymptotic approximation. The theory is applied…

Strongly Correlated Electrons · Physics 2015-05-19 Y. Kakehashi , M. Atiqur R. Patoary , T. Tamashiro

This letter aims to derive the exact relativistic orbital-free kinetic energy density functional for one-particle nuclear systems in one-dimensional case. The kinetic energy is expressed as a functional of both vector and scalar densities.…

Nuclear Theory · Physics 2025-12-25 X. H. Wu , Z. X. Ren , H. Z. Liang , P. W. Zhao

In this paper, we study the problem of identifying the impulse response of a linear time invariant (LTI) dynamical system from the knowledge of the input signal and a finite set of noisy output observations. We adopt an approach based on…

Systems and Control · Computer Science 2015-03-20 Francesco Dinuzzo

A phenomenological coupled exciton model is proposed in order to characterize optical excitations in extended dendrimers. An onsite exciton state is assigned at each phenyl rings and a nearest neighbor hopping integral which obeys the…

Materials Science · Physics 2016-08-31 Kikuo Harigaya

We report the properties of the prompt dipole radiation, produced via a collective bremsstrahlung mechanism, in fusion reactions with exotic beams. We show that the gamma yield is sensitive to the density dependence of the symmetry energy…

Nuclear Theory · Physics 2009-03-04 V. Baran , C. Rizzo , M. Colonna , M. Di Toro , D. Pierroutsakou

We calculate the imaginary part of the frequency-dependent dielectric function of bulk silicon by applying time-dependent density-functional theory based on the exact-exchange (EXX) Kohn-Sham (KS) band structure and the adiabatic…

Materials Science · Physics 2016-01-01 Yong-Hoon Kim , Martin Staedele , Andreas Goerling

Time-dependent density functional theory (TDDFT) is a standard approach for calculating optical excitations of molecules and solids, while ensemble DFT (EDFT) is a promising alternative under development. We introduce ensemble TDDFT…

Chemical Physics · Physics 2026-05-22 Kimberly J. Daas , Steven Crisostomo , Kieron Burke

Neutral atoms have been observed to survive intense laser pulses in high Rydberg states with surprisingly large probability. Only with this Rydberg-state excitation (RSE) included is the picture of intense-laser-atom interaction complete.…

Modeling multiple sampling densities within a hierarchical framework enables borrowing of information across samples. These density random effects can act as kernels in latent variable models to represent exchangeable subgroups or clusters.…

Methodology · Statistics 2026-05-19 Yuliang Xu , Kaixuan Luo , Li Ma

The accurate prediction of singlet and triplet excitation energies is of significant fundamental interest and is critical for many applications. An area of intense research, most calculations of singlet and triplet energies use…

Computational Physics · Physics 2017-05-22 Tonatiuh Rangel , Samia M. Hamed , Fabien Bruneval , Jeffrey B. Neaton

We study light-mediated interactions between spatially separated molecules using real-time quantum electrodynamical time-dependent density functional theory based on the Pauli-Fierz Hamiltonian. An ultrashort delta-kick excitation…

Chemical Physics · Physics 2026-01-22 Yetmgeta Aklilu , Tiany Yang , Cody Covington , Kalman Varga

X-ray spectroscopies, by their high selectivity and sensitivity to the chemical environment around the atoms probed, provide significant insight into the electronic structure of molecules and materials. Interpreting experimental results…

Chemical Physics · Physics 2024-12-23 Wilken Aldair Misael , André Severo Pereira Gomes

The dynamical exchange-correlation kernel $f_{xc}$ of a non-uniform electron gas is an essential input for the time-dependent density functional theory of electronic systems. The long-wavelength behavior of this kernel is known to be of the…

Materials Science · Physics 2009-11-13 V. U. Nazarov , G. Vignale , Y. -C. Chang

We develop a linked cluster method to calculate the spectral weights of many-particle excitations at zero temperature. The dynamical structure factor is expressed as a sum of exclusive structure factors, each representing contributions from…

Strongly Correlated Electrons · Physics 2009-11-10 Chris J. Hamer , Weihong Zheng , Rajiv R. P. Singh

Time-dependent response theories are foundational to the development of algorithms that determine quantum properties of electronic excited states of molecules and periodic systems. They are employed in wave-function, density-functional, and…

Chemical Physics · Physics 2022-11-23 Martín A. Mosquera

The asymmetric Hubbard dimer is used to study the density-dependence of the exact frequency-dependent kernel of linear-response time-dependent density functional theory. The exact form of the kernel is given, and the limitations of the…

Strongly Correlated Electrons · Physics 2018-07-17 D. J. Carrascal , J. Ferrer , N. Maitra , K. Burke

Excitation energies of light-emitting organic conjugated polymers have been investigated with time-dependent density functional theory (TDDFT) within the adiabatic approximation for the dynamical exchange-correlation potential. Our…

Materials Science · Physics 2009-07-06 Jianmin Tao , Sergei Tretiak , Jian-Xin Zhu

A kernel-based framework for spatio-temporal data analysis is introduced that applies in situations when the underlying system dynamics are governed by a dynamic equation. The key ingredient is a representer theorem that involves…

Statistics Theory · Mathematics 2020-11-16 Oleg Szehr , Dario Azzimonti , Laura Azzimonti

Long-range charge transfer excited states are notoriously badly underestimated in time-dependent density functional theory (TDDFT). We resolve how {\it exact} TDDFT captures charge transfer between open-shell species: in particular the role…

Chemical Physics · Physics 2009-11-11 Neepa T. Maitra