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Related papers: Development of a configuration-interaction + all-o…

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We present a detailed study of the Flambaum-Ginges radiative potential method which enables the accurate inclusion of quantum electrodynamics (QED) radiative corrections in a simple manner in atoms, ions, and molecules over the range…

Atomic Physics · Physics 2016-05-18 J. S. M. Ginges , J. C. Berengut

Quantum mechanical few-body systems in reduced dimensionalities can exhibit many interesting properties such as scale-invariance and universality. Analytical descriptions are often available for integer dimensionality, however, numerical…

Quantum Gases · Physics 2019-07-24 F. S. Møller , D. V. Fedorov , A. S. Jensen , N. T. Zinner

We investigate the accuracy of a number of wavefunction based methods at the heart of quantum chemistry for metallic systems. Using Hartree-Fock as a reference, perturbative (M{\o}ller-Plesset, MP) and coupled cluster (CC) theories are used…

Chemical Physics · Physics 2013-10-24 James J. Shepherd , Andreas Grüneis

We present an ab initio method of calculation of isotope shift and relativistic shift in atoms with a few valence electrons. It is based on an energy calculation involving combination of the configuration interaction method and many-body…

Atomic Physics · Physics 2009-08-18 J. C. Berengut , V. V. Flambaum , M. G. Kozlov

In this study, a variety of methods are tested and compared for the numerical solution of the Schr\"odinger equation for few-body systems with explicitely time-dependent Hamiltonians, with the aim to find the optimal one. The configuration…

Quantum Physics · Physics 2013-02-01 Jonas C. Cremon

Accurately describing strong electron correlation in complex systems remains a prominent challenge in computational chemistry as near-term quantum algorithms treating total correlation often require prohibitively deep circuits. Here we…

Computational Engineering, Finance, and Science · Computer Science 2026-04-21 Zhanou Liu , Yuhao Chen , Yingjin Ma , Xiao He , Yuxin Deng

We investigate the basis-set convergence of electronic correlation energies calculated using coupled cluster theory and a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and…

Chemical Physics · Physics 2019-10-03 Andreas Irmler , Andreas Grüneis

We present an approach to calculation of point defect optical and thermal ionization energies based on the highly accurate quantum Monte Carlo methods. The use of an inherently many-body theory that directly treats electron correlation…

Materials Science · Physics 2015-06-11 Elif Ertekin , Lucas K. Wagner , Jeffrey C. Grossman

A systematic method to account for electron correlation in periodic systems which can predict quantitatively correct band structures of non-conducting solids from first principles is presented. Using localized Hartree-Fock orbitals (both…

Other Condensed Matter · Physics 2007-05-23 V. Bezugly , U. Birkenheuer

We present a variational Monte Carlo method that solves the nuclear many-body problem in the occupation number formalism exploiting an artificial neural network representation of the ground-state wave function. A memory-efficient version of…

In this work we demonstrate that the heat bath configuration interaction (HCI) and its semistochastic extension can be used to treat relativistic effects and electron correlation on an equal footing in large active spaces to calculate the…

Chemical Physics · Physics 2018-11-08 Bastien Mussard , Sandeep Sharma

Traditional multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis (OB). For atoms with complicated shell structures, a large OB is needed to saturate all the…

Atomic Physics · Physics 2015-06-12 S. Verdebout , P. Rynkun , P. Jönsson , G. Gaigalas , C. Froese Fischer , M. Godefroid

Treating electron correlation more accurately and efficiently is at the heart of the development of electronic structure methods. In the present work, we explore the use of stochastic approaches to evaluate high-order electron correlation…

Chemical Physics · Physics 2020-01-29 Zhendong Li

We outline a generic, flexible, modular, yet efficient framework to the computation of energies and states for general nanoscopic systems with a focus on semiconductor quantum dots. The approach utilizes the configuration interaction…

Computational Physics · Physics 2007-05-23 Jordan Kyriakidis

In recent years the femtoscopy technique has been used by the ALICE Collaboration in small colliding systems at the LHC to investigate the strong-interaction of hadron pairs in the low-energy regime. The extension of this technique to the…

In the present paper, the correction due to the thermal interaction of two charges to the recombination and ionization processes for the hydrogen atom is considered. The evaluation is based on a rigorous quantum electrodynamic (QED)…

Atomic Physics · Physics 2025-09-11 J. Triaskin , T. Zalialiutdinov , A. Anikin , D. Solovyev

Through the development of many-body methodology and algorithms, it has become possible to describe quantum systems composed of a large number of particles with great accuracy. Essential to all these methods is the application of auxiliary…

Nuclear Theory · Physics 2018-04-18 Christopher Körber , Evan Berkowitz , Thomas Luu

Current methods to describe the thermodynamic behavior of many-particle systems are often based on perturbation theory with an unperturbed system consisting of free particles. Therefore, only a few methods are able to describe both strongly…

Strongly Correlated Electrons · Physics 2009-10-30 Holger Koehler , Matthias Vojta , Klaus W. Becker

The method of lowest-order constrained variational, which predicts reasonably the nuclear matter semi-empirical data is used to calculate the equation of state of beta-stable matter at finite temperature. The Reid soft-core with and without…

Nuclear Theory · Physics 2016-09-08 M. Modarres , H. R. Moshfegh

In this paper we consider the evaluation of the Araki-Sucher correction for arbitrary many-electron atomic and molecular systems. This contribution appears in the leading order quantum electrodynamics corrections to the energy of a bound…

Chemical Physics · Physics 2017-12-06 Justyna G. Balcerzak , Michał Lesiuk , Robert Moszynski