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

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Full configuration interaction (FCI) solvers are limited to small basis sets due to their expensive computational costs. An optimal orbital selection for FCI (OptOrbFCI) is proposed to boost the power of existing FCI solvers to pursue the…

Chemical Physics · Physics 2020-09-01 Yingzhou Li , Jianfeng Lu

To describe the interactions in magnetically soft particle systems either numerical full-field methods or dipole models are used. Whereas the former are computationally challenging, simple dipole interactions are largely underestimating the…

Classical Physics · Physics 2026-04-16 Dirk Romeis

Highly accurate results for the homogeneous electron gas (HEG) have only been achieved to date within a diffusion Monte Carlo (DMC) framework. Here, we introduce a newly developed stochastic technique, Full Configuration Interaction Quantum…

Quantum Gases · Physics 2012-02-22 James J. Shepherd , George Booth , Andreas Grüneis , Ali Alavi

In a previous paper we proposed a Projected Configuration Interaction method that uses sets of axially deformed single particle states to build up the many body basis. We show that the choice of the basis set is essential for the efficiency…

Nuclear Theory · Physics 2013-05-29 Zao-Chun Gao , Mihai Horoi , Y. S. Chen

The many-body states in an extended Fermionic Molecular Dynamics approach are flexible enough to allow the description of nuclei with shell model nature as well as nuclei with cluster and halo structures. Different many-body configurations…

Nuclear Theory · Physics 2009-11-10 T. Neff , H. Feldmeier

We report no-core solutions for properties of light nuclei with three different approaches in order to assess the accuracy and convergence rates of each method. Full configuration interaction (FCI), Monte Carlo shell model (MCSM) and no…

Nuclear Theory · Physics 2012-11-09 T. Abe , P. Maris , T. Otsuka , N. Shimizu , Y. Utsuno , J. P. Vary

In correlated electron materials, the application of many-body techniques for the study of interaction effects or unconventional superconductivity often requires the formulation of an effective low-energy model that contains only the…

Strongly Correlated Electrons · Physics 2013-05-30 Carsten Honerkamp

Over the past few decades, there has been a rapid improvement in computational power as well as techniques to simulate the real world phenomenon which has enabled us to understand the physics and develop new systems which outperform the…

Computational Physics · Physics 2020-06-09 Sumant R Morab , Atul Sharma

We explore many-body entanglement in spinful Fermi gases with short-range interactions, for metrology purposes. We characterize the emerging quantum phases via Density-Matrix Renormalization Group simulations and quantify their entanglement…

Quantum Gases · Physics 2019-08-30 Leonardo Lucchesi , Maria Luisa Chiofalo

Energy-based fragmentation methods approximate the potential energy of a molecular system as a sum of contribution terms built from the energies of particular subsystems. Some such methods reduce to truncations of the many-body expansion…

Numerical Analysis · Mathematics 2025-09-25 James Barker , Michael Griebel , Jan Hamaekers

Confined quantum systems involving $N$ identical interacting fermions are found in many areas of physics, including condensed matter, atomic, nuclear and chemical physics. In a previous series of papers, a manybody perturbation method that…

Quantum Physics · Physics 2015-06-18 D. K. Watson

Neutral uranium (U I) is a very difficult atom for theoretical calculations due to a large number of valence electrons, six, strong valence-valence and valence-core correlations, high density of states, and relativistic effects.…

Atomic Physics · Physics 2020-10-14 Igor M. Savukov

In the derivation of low-energy effective models for solids targeting the bands near the Fermi level, the constrained random phase approximation (cRPA) has become an appreciated tool to compute the effective interactions. The Wick-ordered…

Strongly Correlated Electrons · Physics 2015-07-15 Michael Kinza , Carsten Honerkamp

Quantum computers are appealing for their ability to solve some tasks much faster than their classical counterparts. It was shown in [Aspuru-Guzik et al., Science 309, 1704 (2005)] that they, if available, would be able to perform the full…

Quantum Physics · Physics 2010-11-19 Libor Veis , Jiří Pittner

The formalism based on correlated basis functions and the cluster expansion technique has been recently employed to derive an effective interaction from a realistic nuclear hamiltonian. To gauge the reliability of this scheme, we perform a…

Nuclear Theory · Physics 2015-08-17 Angela Mecca , Alessandro Lovato , Omar Benhar , Artur Polls

We study theoretically the phase diagram of strongly coupled two-dimensional Bose-Fermi mixtures interacting with attractive short-range potentials as a function of the particle densities. We focus on the limit where the size of the bound…

Quantum Gases · Physics 2023-05-31 Jonas von Milczewski , Félix Rose , Richard Schmidt

We investigate the effective interaction between Cooper-pair molecules in the st rong-coupling BEC regime of a superfluid Fermi gas with a Feshbach resonance. Our work uses a path integral formulation and a renormalization group (RG) analy…

Superconductivity · Physics 2009-11-11 Y. Ohashi

The nuclear-electronic orbital (NEO) approach incorporates nuclear quantum effects into quantum chemistry calculations by treating specified nuclei quantum mechanically, equivalently to the electrons. Within the NEO framework, excited…

Chemical Physics · Physics 2025-03-19 Christopher L. Malbon , Sharon Hammes-Schiffer

We present NECI, a state-of-the-art implementation of the Full Configuration Interaction Quantum Monte Carlo algorithm, a method based on a stochastic application of the Hamiltonian matrix on a sparse sampling of the wave function. The…

Finding the ground state of a fermionic Hamiltonian using quantum Monte Carlo is a very difficult problem, due to the Fermi sign problem. While still scaling exponentially, full configuration-interaction Monte Carlo (FCI-QMC) mitigates some…

Computational Physics · Physics 2013-12-17 Michael H. Kolodrubetz , Bryan K. Clark