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Related papers: Time-dependent restricted-active-space self-consis…

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Time-dependent Hartree-Fock (TDHF) is one of the fundamental post-Hartree-Fock (HF) methods to describe excited states. In its Tamm-Dancoff form, equivalent to Configuration Interaction Singles, it is still widely used and particularly…

Chemical Physics · Physics 2024-11-18 Uday Panta , David A. Strubbe

Favorably scaling numerical time-dependent many-electron techniques such as time-dependent density functional theory (TDDFT) with adiabatic exchange-correlation potentials typically fail in capturing highly correlated electron dynamics. We…

Atomic Physics · Physics 2013-11-25 M. Brics , D. Bauer

We present a numerical implementation of the infinite-range exterior complex scaling (irECS) [Phys. Rev. A 81, 053845 (2010)] as an efficient absorbing boundary to the time-dependent complete-active-space self-consistent field (TD-CASSCF)…

Atomic Physics · Physics 2018-03-07 Yuki Orimo , Takeshi Sato , Armin Scrinzi , Kenichi L. Ishikawa

The time-dependent density functional based tight-binding (TD-DFTB) approach is generalized to account for fractional occupations. In addition, an on-site correction leads to marked qualitative and quantitative improvements over the…

Materials Science · Physics 2013-02-15 A. Domínguez , B. Aradi , T. Frauenheim , V. Lutsker , T. A. Niehaus

We employ the time-dependent Hartree-Fock (TDHF) method to study various aspects of the reactions utilized in searches for superheavy elements. These include capture cross-sections, quasifission, prediction of $P_{\mathrm{CN}}$, and other…

Nuclear Theory · Physics 2016-04-12 A. S. Umar , V. E. Oberacker

Complete active space self-consistent field (CASSCF) computations can be realized at polynomial cost via the variational optimization of the active-space two-electron reduced-density matrix (2-RDM). Like conventional approaches to CASSCF,…

Chemical Physics · Physics 2018-12-10 Mohammad Mostafanejad , A. Eugene DePrince

We present a variational augmentation procedure to optimize the exponents of Gaussian continuum basis sets for simulating strong-field laser ionization phenomena such as higher harmonic generation (HHG) in atoms and ions using the…

Chemical Physics · Physics 2023-07-04 Sai Vijay Bhaskar Mocherla , Raghunathan Ramakrishnan

In this work we present the theoretical framework for the solution of the time-dependent Schr\"{o}dinger equation (TDSE) of atomic and molecular systems under strong electromagnetic fields with the configuration space of the electron's…

Atomic Physics · Physics 2009-11-13 L. A. A. Nikolopoulos , J. S. Parker , K. T. Taylor

Microscopic methods and tools to describe nuclear dynamics have considerably been improved in the past few years. They are based on the time-dependent Hartree-Fock (TDHF) theory and its extensions to include pairing correlations and quantum…

Nuclear Theory · Physics 2018-09-13 C. Simenel , A. S. Umar

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

In this paper, we investigate the effects of full electronic correlation on the high harmonic generation in the helium atom subjected to laser pulses of extremely high intensity. To do this, we perform real-time propagations of the helium…

Chemical Physics · Physics 2022-05-18 Aleksander P. Woźniak , Michał Przybytek , Maciej Lewenstein , Robert Moszyński

The multiconfigurational time-dependent Hartree-Fock method (MCTDHF) is applied for simulations of the two-photon ionization of Helium. We present results for the single- and double ionization from the groundstate for photon energies in the…

Atomic Physics · Physics 2011-12-30 D. Hochstuhl , M. Bonitz

Time-Dependent Density Functional Theory (TDDFT) has recently been extended to describe many-body open quantum systems (OQS) evolving under non-unitary dynamics according to a quantum master equation. In the master equation approach,…

Chemical Physics · Physics 2015-05-18 David G. Tempel , Mark A. Watson , Roberto Olivares-Amaya , Alán Aspuru-Guzik

We present analytic gradients and derivative couplings for the simplest possible multireference configuration interaction method, CIS-1D, an electronic structure ansatz that includes all single excitations and one lone double excitation on…

Chemical Physics · Physics 2021-02-15 Hung-Hsuan Teh , Joseph E. Subotnik

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the…

Quantum Physics · Physics 2009-11-13 Xiao Zheng , Fan Wang , Chi Yung Yam , Yan Mo , GuanHua Chen

We introduce the time-dependent restricted active space Configuration Interaction method to solve the time-dependent Schr\"odinger equation for many-electron atoms, and particularly apply it to the treatment of photoionization processes in…

Atomic Physics · Physics 2013-05-30 David Hochstuhl , Michael Bonitz

Modeling chemical reactions with quantum chemical methods is challenging when the electronic structure varies significantly throughout the reaction, as well as when electronic excited states are involved. Multireference methods such as…

We present the first calculations of the inelastic part of the dynamical structure factor (DSF) for warm dense matter (WDM) using Time-Dependent Orbital-Free Density Functional Theory (TD-OF-DFT) and Mixed-Stochastic-Deterministic (mixed)…

Plasma Physics · Physics 2024-11-05 Alexander J. White

This paper introduces a spectral analysis of time-seires data derived from real-time time-dependent density functional theory (TDDFT) using Singular Spectrum Analysis (SSA). TDDFT is a robust method for obtaining molecular excited states…

Computational Physics · Physics 2025-10-02 Naoki Tani , Satoru S. Kano , Yasunari Zempo

The increasing need to simulate the dynamics of photoexcited molecular and nanosystems in the sub-picosecond regime demands new efficient tools able to describe the quantum nature of matter at a low computational cost. By combining the…