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Simulating fully kinetic, two-species plasmas is computationally challenging due to the stiff multiscale dynamics of electrons and ions. While enforcing a quasi-neutral time evolution mitigates this stiffness, it requires an electric…

Plasma Physics · Physics 2026-04-24 M. Pelkner , K. Hallatschek , M. Raeth

Owing to its numerical simplicity, a two-dimensional two-electron model atom, with each electron moving in one direction, is an ideal system to study non-perturbatively a fully correlated atom exposed to a laser field. Frequently made…

Atomic Physics · Physics 2009-10-30 D. Bauer

The real-time electronic dynamics on material surfaces is critically important to a variety of applications. However, their simulations have remained challenging for conventional methods such as the time-dependent density-functional theory…

Chemical Physics · Physics 2015-06-16 Rulin Wang , Dong Hou , Xiao Zheng

Few-electron systems confined in two-dimensional parabolic quantum dots at high magnetic fields are studied by the Hartree-Fock (HF) and exact diagonalization methods. A generalized multicenter Gaussian basis is proposed in the HF method. A…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. Szafran , S. Bednarek , J. Adamowski , M. B. Tavernier , E. Anisimovas , F. M. Peeters

We present a new formulation of the time-dependent self-interaction correction (TDSIC). It is derived variationally obeying explicitly the constraints on orthonormality of the occupied single-particle orbitals. The thus emerging rather…

Quantum Physics · Physics 2009-03-02 J. Messud , P. M. Dinh , P. -G. Reinhard , E. Suraud

Linear response time dependent density functional theory (TDDFT), which builds upon configuration interaction singles (CIS) and TD-Hartree-Fock (TDHF), is the most widely used class of excited state quantum chemistry methods and is often…

Chemical Physics · Physics 2019-10-14 Diptarka Hait , Adam Rettig , Martin Head-Gordon

We present a computational study of the laser-driven quantum dynamics of positronium (Ps), PsH, and PsCl at the time-dependent Hartree-Fock level of theory. To eliminate finite-basis effects and to properly capture continuum dynamics, we…

The density-constrained time-dependent Hartree-Fock (DC-TDHF) theory is a fully microscopic approach for calculating heavy-ion interaction potentials and fusion cross sections below and above the fusion barrier. We discuss recent…

Nuclear Theory · Physics 2017-08-23 A. S. Umar , V. E. Oberacker , J. A. Maruhn , R. Keser

Understanding the real-time evolution of many-electron quantum systems is essential for studying dynamical properties in condensed matter, quantum chemistry, and complex materials, yet it poses a significant theoretical and computational…

Strongly Correlated Electrons · Physics 2024-11-07 Jannes Nys , Gabriel Pescia , Alessandro Sinibaldi , Giuseppe Carleo

A multiscale model based on the coupling of the multiconfigurational self-consistent field (MCSCF) method and the classical atomistic polarizable Fluctuating Charges (FQ) force field is presented. The resulting MCSCF/FQ approach is…

We carried out a simulation of heavy ion collision using a time-dependent density functional theory. We call it the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) which can describe nuclear dynamics in…

Nuclear Theory · Physics 2015-06-12 Shuichiro Ebata

A clear understanding of the mechanisms that control the electron dynamics in strong laser field is still a challenge that requires to be interpreted by advanced theory. Development of accurate theoretical and computational methods, able to…

A phase space theory approach for treating dynamical behaviour of Bose-Einstein condensates applicable to situations such as interferometry with BEC in time-dependent double well potentials is presented. Time-dependent mode functions are…

Quantum Gases · Physics 2015-06-24 B. J. Dalton

We consider the dynamics of electrons in combined strong laser and Coulomb fields. Under a timescale separation condition, we reduce this dynamics to a guiding-center framework. More precisely, we derive a hierarchy of models for the…

Chaotic Dynamics · Physics 2018-11-28 Jonathan Dubois , S. Berman , C. Chandre , T. Uzer

Accurately characterizing the intensity and duration of strong-field femtosecond pulses within the interaction volume is crucial for attosecond science. However, this remains a major bottleneck, limiting accuracy of the strong-field, and in…

Atomic Physics · Physics 2025-04-25 Noam Shlomo , Eugene Frumker

Fragmentation methods applied to multireference wave functions constitute a road towards the application of highly accurate ab initio wave function calculations to large molecules and solids. However, it is important for reproducibility and…

Chemical Physics · Physics 2020-07-23 Matthew R. Hermes , Laura Gagliardi

We present an efficient and systematically convergent approach to all-electron real-time time-dependent density functional theory (TDDFT) calculations using a mixed basis, termed as enriched finite element (EFE) basis. The EFE basis…

Chemical Physics · Physics 2022-10-27 Bikash Kanungo , Nelson D. Rufus , Vikram Gavini

Taking N2 and O2 as examples, we theoretically study the post-ionization dynamics of molecules in strong laser fields using a density matrix method for open systems, focusing on the effect of ionization-produced coherence on the dynamics of…

Atomic Physics · Physics 2024-12-12 Shan Xue , Wenli Yang , Ping Li , Yuxuan Zhang , Pengji Ding , Song-Feng Zhao , Hongchuan Du , Anh-Thu Le

Analytic energy gradients are presented for a variational two-electron reduced-density-matrix-driven complete active space self-consistent field (v2RDM-CASSCF) procedure that employs the density-fitting (DF) approximation to the…

Chemical Physics · Physics 2018-11-29 J. Wayne Mullinax , Evgeny Epifanovsky , Gergely Gidofalvi , A. Eugene DePrince

We propose a new method of calculating electronically excited states that combines a density functional theory (DFT) based ground state calculation with a linear response treatment that employs approximations used in the time-dependent…

Chemical Physics · Physics 2016-05-11 Robert Rüger , Erik van Lenthe , Thomas Heine , Lucas Visscher