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We provide a methodology for generating interatomic potentials for use in classical molecular dynamics simulations of atomistic phenomena occurring at energy scales ranging from lattice vibrations to crystal defects to high energy…

Materials Science · Physics 2009-12-03 Pratyush Tiwary , Axel van de Walle , Niels Grønbech-Jensen

A general concept for the derivation of symmetry-based pseudo spin Hamiltonians is described. It systematically bridges the gap between the atomistic basis and various pseudo spin models presented in literature. It thus allows the…

Condensed Matter · Physics 2007-05-23 Boris Neubert , Michel Pleimling , Rolf Siems

Engineering a Hamiltonian system with tunable interactions provides opportunities to optimize performance for quantum sensing and explore emerging phenomena of many-body systems. An optical lattice clock based on partially delocalized…

We present a new variational model for computing the electronic first-order density matrix of a crystalline material in presence of a local defect. A natural way to obtain variational discretizations of this model is to expand the…

Other Condensed Matter · Physics 2009-11-13 Eric Cances , Amelie Deleurence , Mathieu Lewin

We present a wavefunction-based approach to correlated ab initio calculations on crystalline insulators of infinite extent. It uses the representation of the occupied and the unoccupied (virtual) single-particle states of the infinite solid…

Condensed Matter · Physics 2009-10-31 Alok Shukla , Michael Dolg , Peter Fulde , Hermann Stoll

We present a new method which combines Car-Parrinello and Born-Oppenheimer molecular dynamics in order to accelerate density functional theory based ab-initio simulations. Depending on the system a gain in efficiency of one to two orders of…

Materials Science · Physics 2007-05-23 Thomas D. Kühne , Matthias Krack , Fawzi R. Mohamed , Michele Parrinello

The H\"uckel Hamiltonian is an incredibly simple tight-binding model famed for its ability to capture qualitative physics phenomena arising from electron interactions in molecules and materials. Part of its simplicity arises from using only…

Quantum computing has shown great potential in various quantum chemical applications such as drug discovery, material design, and catalyst optimization. Although significant progress has been made in quantum simulation of simple molecules,…

Quantum Physics · Physics 2023-05-30 Changsu Cao , Jinzhao Sun , Xiao Yuan , Han-Shi Hu , Hung Q. Pham , Dingshun Lv

The problem of construction of the Wannier functions (WFs) in a restricted Hilbert space of eigenstates of the one-electron Hamiltonian $\hat{H}$ (forming the so-called low-energy part of the spectrum) can be formulated in several different…

Strongly Correlated Electrons · Physics 2007-05-23 I. V. Solovyev , Z. V. Pchelkina , V. I. Anisimov

Tunneling of electrons through rotor-stator anthracene aldehyde molecular interfaces is studied with a combined ab initio and model approach. Molecular electronic structure calculated from first principles is utilized to model different…

Chemical Physics · Physics 2016-05-27 Irina Petreska , Vladimir Ohanesjan , Ljupco Pejov , Ljupco Kocarev

An interacting lattice model describing the subspace spanned by a set of strongly-correlated bands is rigorously coupled to density functional theory to enable ab initio calculations of geometric and topological material properties. The…

Strongly Correlated Electrons · Physics 2019-03-26 Ryan Requist , E. K. U. Gross

An effective low-energy model describing magnetic properties of alkali-cluster-loaded sodalites is derived by {\em ab initio} downfolding. We start with constructing an extended Hubbard model for maximally localized Wannier functions. {\em…

Strongly Correlated Electrons · Physics 2010-10-20 Kazuma Nakamura , Takashi Koretsune , Ryotaro Arita

Density matrix embedding theory (Phys. Rev. Lett. 109, 186404 (2012)) and density embedding theory ((Phys. Rev. B 89, 035140 (2014)) have recently been introduced for model lattice Hamiltonians and molecular systems. In the present work,…

Chemical Physics · Physics 2016-11-25 Ireneusz W. Bulik , Weibing Chen , Gustavo E. Scuseria

We derive an electron-vibration model Hamiltonian in a quantum chemical framework, and explore the extent to which such a Hamiltonian can capture key effects of nonadiabatic dynamics. The model Hamiltonian is a simple two-body operator, and…

Chemical Physics · Physics 2021-02-03 Thomas Dresselhaus , Callum B. A. Bungey , Peter J. Knowles , Frederick R. Manby

A model subspace configuration interaction method is developed to obtain chemically accurate electron correlations by diagonalising a very compact effective Hamiltonian of realistic molecule. The construction of the effective Hamiltonian is…

Chemical Physics · Physics 2022-10-18 Jiasheng Li , Jun Yang

We present a non-standard Hubbard model applicable to arbitrary single-particle potential profiles and inter-particle interactions. Our approach involves a novel treatment of Wannier functions, free from the ambiguities of conventional…

Strongly Correlated Electrons · Physics 2024-05-14 M. Zendra , F. Borgonovi , G. L. Celardo , S. Gurvitz

We present optimized tight-binding models with atomic orbitals to improve \textit{ab initio} tight-binding models constructed by truncating full density functional theory (DFT) Hamiltonian based on localized orbitals. Retaining qualitative…

Mesoscale and Nanoscale Physics · Physics 2024-02-20 Sejoong Kim

We present a minimal non-Hermitian model where a topologically nontrivial complex energy spectrum is induced by inter-particle interactions. Our model consists of a one-dimensional chain with a dynamical non-Hermitian gauge field with…

Quantum Physics · Physics 2023-03-23 William N Faugno , Tomoki Ozawa

"Realistic modeling" is a new direction of electronic structure calculations, where the main emphasis is made on the construction of some effective low-energy model entirely within a first-principle framework. Ideally, it is a model in…

Strongly Correlated Electrons · Physics 2011-06-10 Igor Solovyev

This is an introductory review of the physics of topological quantum matter with cold atoms. Topological quantum phases, originally discovered and investigated in condensed matter physics, have recently been explored in a range of different…

Quantum Gases · Physics 2019-04-03 Dan-Wei Zhang , Yan-Qing Zhu , Y. X. Zhao , Hui Yan , Shi-Liang Zhu