English
Related papers

Related papers: Many-Body Expanded Full Configuration Interaction.…

200 papers

Multi-configurational electronic structure theory delivers the most versatile approximations to many-electron wavefunctions, flexible enough to deal with all sorts of transformations, ranging from electronic excitations, to open-shell…

Chemical Physics · Physics 2024-05-07 Kalman Szenes , Maximilian Moerchen , Paul Fischill , Markus Reiher

We introduce the pCI software package for high-precision atomic structure calculations. The standard method of calculation is based on the configuration interaction (CI) method to describe valence correlations, but can be extended to attain…

Atomic Fermi gases provide an ideal platform for studying the pairing and superfluid physics, using a Feshbach resonance between closed channel molecular states and open channel scattering states. Of particular interest is the strongly…

In this paper we describe a computational model for the simulation of fluid-structure interaction problems based on a fictitious domain approach. We summarize the results presented over the last years when our research evolved from the…

Numerical Analysis · Mathematics 2021-04-29 Daniele Boffi , Lucia Gastaldi

We present a systematic coarse-graining (CG) strategy for many particle molecular systems based on cluster expansion techniques. We construct a hierarchy of coarse-grained Hamiltonians with interaction potentials consisting of two, three…

Soft Condensed Matter · Physics 2017-10-11 Anastasios Tsourtis , Vagelis Harmandaris , Dimitrios Tsagkarogiannis

Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular…

Chemical Physics · Physics 2015-09-30 Anders S. Christensen , Marcus Elstner , Qiang Cui

Many-body correlations characterizing the Constrained Molecular Dynamics (CoMD)are analyzed in the case of finite and zero range effective microscopic interactions. The study begins by analyzing the case of infinite nuclear matter at zero…

Nuclear Theory · Physics 2023-11-02 Massimo Papa

The recent theoretical discovery of fractional Chern insulators (FCIs) has provided an important new way to realize topologically ordered states in lattice models. In earlier works, on-site and nearest neighbor Hubbard-like interactions…

Strongly Correlated Electrons · Physics 2013-11-05 Zhao Liu , Emil J. Bergholtz , Eliot Kapit

Bound states in the continuum (BICs), referring to spatially localized bound states with energies falling within the range of extended modes, have been extensively investigated in single-particle systems, leading to diverse applications in…

Mesoscale and Nanoscale Physics · Physics 2024-09-17 Na Sun , Weixuan Zhang , Hao Yuan , Xiangdong Zhang

The objective of this work is the development of a novel finite element formulation describing the contact interaction of slender beams in complex 3D configurations involving arbitrary beam-to-beam orientations. It is shown in a…

Computational Engineering, Finance, and Science · Computer Science 2018-05-28 Christoph Meier , Alexander Popp , Wolfgang A. Wall

An accurate description of electron correlation is one of the most challenging problems in quantum chemistry. The exact electron correlation can be obtained by means of full configuration interaction (FCI). A simple strategy for…

Chemical Physics · Physics 2021-05-14 Jae Woo Park

Full configuration interaction quantum Monte Carlo (FCIQMC) is a state-of-the-art stochastic electronic structure method, providing a methodology to compute FCI-level state energies of molecular systems within a quantum chemical basis.…

Chemical Physics · Physics 2022-04-29 Tonghuan Jiang , Wei Fang , Ali Alavi , Ji Chen

We compute the equation of state, the gap as well as the density fluctuations of a two-component superfluid Fermi gas over the whole range of BEC-BCS crossover at vanishing temperature within the functional renormalisation group approach.…

Quantum Gases · Physics 2023-07-28 Bruno M. Faigle-Cedzich , Jan M. Pawlowski , Christof Wetterich

The virtues of an effective field theory (EFT) approach to many-body problems are illustrated by deriving the expansion for the energy of an homogeneous, interacting Fermi gas at low density and zero temperature. A renormalization scheme…

Nuclear Theory · Physics 2009-11-06 H. -W. Hammer , R. J. Furnstahl

The physics of quantum degenerate Fermi gases in uniform as well as in harmonically trapped configurations is reviewed from a theoretical perspective. Emphasis is given to the effect of interactions which play a crucial role, bringing the…

Other Condensed Matter · Physics 2009-11-13 Stefano Giorgini , Lev P. Pitaevskii , Sandro Stringari

Non-perturbative aspects of the quantum many-body problem are revisited, discussed and advanced in the equation of motion framework. We compare the approach to the two-fermion response function truncated on the two-body level by the cluster…

Nuclear Theory · Physics 2020-01-01 Elena Litvinova , Peter Schuck

We present a theory of measurement-induced interference for weakly interacting Bose-Einstein condensed (BEC) gases. The many-body state resulting from the evolution of an initial fragmented (Fock) state can be approximated as a continuous…

Statistical Mechanics · Physics 2009-11-13 G. S. Paraoanu

Understanding the structure and reactions of nuclei from first principles has been a long-standing goal of nuclear physics. In this respect, few- and many-body systems provide a unique laboratory for studying nuclear interactions. In the…

Nuclear Theory · Physics 2021-11-10 Maria Piarulli , Rocco Schiavilla

The development of polynomial cost solvers for correlated quantum impurity models, with controllable errors, is a central challenge in quantum many-body physics, where these models find applications ranging from nano-science to the…

Strongly Correlated Electrons · Physics 2012-12-21 Dominika Zgid , Emanuel Gull , Garnet Chan

This chapter discusses contemporary quantum chemical methods and provides general insights into modern electronic structure theory with a focus on heavy-element-containing compounds. We first give a short overview of relativistic…

Chemical Physics · Physics 2020-02-18 Aleksandra Leszczyk , Paweł Tecmer , Katharina Boguslawski