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Related papers: Local Relativistic Exact Decoupling

200 papers

We use density-matrix renormalization group, applied to a one-dimensional model of continuum Hamiltonians, to accurately solve chains of hydrogen atoms of various separations and numbers of atoms. We train and test a machine-learned…

Strongly Correlated Electrons · Physics 2016-12-28 Li Li , Thomas E. Baker , Steven R. White , Kieron Burke

We construct the complementary short-range correlation relativistic local-density-approximation functional to be used in relativistic range-separated density-functional theory based on a Dirac-Coulomb Hamiltonian in the no-pair…

Chemical Physics · Physics 2021-05-26 Julien Paquier , Julien Toulouse

By using the properties of orthogonal polynomials, we present an exact unitary transformation that maps the Hamiltonian of a quantum system coupled linearly to a continuum of bosonic or fermionic modes to a Hamiltonian that describes a…

Quantum Physics · Physics 2010-10-04 Alex W. Chin , Ángel Rivas , Susana F. Huelga , Martin B. Plenio

Quantum entanglement is considered, by and large, to be a very delicate and non-robust phenomenon that is very hard to maintain in the presence of noise, or non-zero temperatures. In recent years however, and motivated, in part, by a quest…

Quantum Physics · Physics 2017-02-27 Lior Eldar

The relative equilibria of a symmetric Hamiltonian dynamical system are the critical points of the so-called augmented Hamiltonian. The underlying geometric structure of the system is used to decompose the critical point equations and…

Differential Geometry · Mathematics 2007-05-23 Pascal Chossat , Debra Lewis , Juan-Pablo Ortega , Tudor S. Ratiu

In this work, we propose an efficient and accurate computational method to evaluate the many-potential $\alpha\left(Z\alpha\right)^{n\ge3}$ vacuum polarization density of hydrogen-like atoms within the finite-basis approximation of the…

Atomic Physics · Physics 2023-07-26 Maen Salman , Trond Saue

We study the entanglement Hamiltonian of two disjoint blocks in the harmonic chain on the line and in its ground state. In the regime of large mass, the non vanishing terms are only the on-site and the nearest-neighbour ones. Analytic…

Statistical Mechanics · Physics 2025-03-26 Francesco Gentile , Andrei Rotaru , Erik Tonni

Embedding calculations that find approximate solutions to the Schr\"{o}dinger equation for large molecules and realistic solids are performed commonly in a three step procedure involving (i) construction of a model system with effective…

Strongly Correlated Electrons · Physics 2016-11-15 Alexander A. Rusakov , Jordan J. Phillips , Dominika Zgid

The article deals with the extension of the relativistic double-ionization equation-of-motion coupled-cluster (DI-EOMCC) method [H. Pathak et al. Phys. Rev. A 90, 010501(R) (2014)] for the molecular systems. The Dirac-Coulomb (DC)…

Chemical Physics · Physics 2020-04-22 Himadri Pathak , Sudip Sasmal , Kaushik Talukdar , Malaya K. Nayak , Nayana Vaval , Sourav Pal

Exactly solvable Hamiltonians are useful in the study of quantum many-body systems using quantum computers. In the variational quantum eigensolver, a decomposition of the target Hamiltonian into exactly solvable fragments can be used for…

Quantum Physics · Physics 2024-02-15 Smik Patel , Artur F. Izmaylov

The exact and phaseless variants of Auxiliary-Field Quantum Monte Carlo (AFQMC) have been shown to be capable of producing accurate ground-state energies for a wide variety of systems including those which exhibit substantial electron…

Chemical Physics · Physics 2017-07-25 James Shee , Shiwei Zhang , David R. Reichman , Richard A. Friesner

This paper derives master equations for an atomic two-level system for a large set of unitarily equivalent Hamiltonians without employing the rotating wave and certain Markovian approximations. Each Hamiltonian refers to physically…

Quantum Physics · Physics 2015-06-03 Adam Stokes , Andreas Kurcz , Tim P. Spiller , Almut Beige

Theory can provide important support at all the stages of spectroscopic experiments, from planning the measurements to the interpretation of the results. Such support is particularly valuable for the challenging experiments on heavy,…

Atomic Physics · Physics 2025-09-19 L. F. Pašteka , E. Eliav , M. L. Reitsma , A. Borschevsky

Drachmann's regularization approach is implemented for floating explicitly correlated Gaussians (fECGs) and molecular systems. Earlier applications of drachmannized relativistic corrections for molecular systems were hindered due to the…

Chemical Physics · Physics 2024-06-11 Balázs Rácsai , Dávid Ferenc , Ádám Margócsy , Edit Mátyus

Computationally efficient and accurate quantum mechanical approximations to solve the many-electron Schr\"odinger equation are at the heart of computational materials science. In that respect the coupled cluster hierarchy of methods plays a…

Materials Science · Physics 2022-01-11 Tina N. Mihm , Tobias Schäfer , Sai Kumar Ramadugu , Andreas Grüneis , James J. Shepherd

In this paper, we address the challenge of obtaining a comprehensive and symmetric representation of point particle groups, such as atoms in a molecule, which is crucial in physics and theoretical chemistry. The problem has become even more…

Chemical Physics · Physics 2024-02-13 Jigyasa Nigam , Sergey N. Pozdnyakov , Kevin K. Huguenin-Dumittan , Michele Ceriotti

The similarity renormalization group is used to transform Dirac Hamiltonian into a diagonal form, which the upper (lower) diagonal element becomes an operator describing Dirac (anti-)particle. The eigenvalues of the operator are verfied to…

Nuclear Theory · Physics 2015-06-04 Jian-You Guo

In this paper we examine the use of low-rank approximations for the handling of radiation boundary conditions in a transient heat equation given a cavity radiation setting. The finite element discretization that arises from cavity radiation…

Numerical Analysis · Mathematics 2023-05-12 Ivan Baburin , Jonas Ballani , John W. Peterson , David Knezevic

The standard mixed finite element approximations of Hodge Laplace problems associated with the de Rham complex are based on proper discrete subcomplexes. As a consequence, the exterior derivatives, which are local operators, are computed…

Numerical Analysis · Mathematics 2017-09-26 Jeonghun J. Lee , Ragnar Winther

Symmetry considerations are at the core of the major frameworks used to provide an effective mathematical representation of atomic configurations that is then used in machine-learning models to predict the properties associated with each…

Chemical Physics · Physics 2021-12-22 Jigyasa Nigam , Michael Willatt , Michele Ceriotti