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Related papers: Approaching the Full Configuration Interaction Low…

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Preparing low energy states is a central challenge in quantum computing and quantum complexity theory. Several known approaches to prepare low energy states often get stuck in suboptimal states, such as high energy eigenstates (or low…

Quantum Physics · Physics 2026-03-17 Anurag Anshu

An analysis of the network defined by the potential energy minima of multi-atomic systems and their connectivity via reaction pathways that go through transition states allows to understand important characteristics like thermodynamic,…

Materials Science · Physics 2016-08-03 Bastian Schaefer , Stefan Goedecker

We propose using the wave function generated by the quantum selected configuration interaction (QSCI) method as the trial wave function in phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC). In the QSCI framework, electronic…

We introduce a family of methods for the full configuration interaction problem in quantum chemistry, based on the fast randomized iteration (FRI) framework [L.-H. Lim and J. Weare, SIAM Rev. 59, 547 (2017)]. These methods, which we term…

Chemical Physics · Physics 2023-09-25 Samuel M. Greene , Robert J. Webber , Jonathan Weare , Timothy C. Berkelbach

We study normal state properties of an interacting Fermi gas in an isotropic harmonic trap of arbitrary dimensions. We exactly calculate the first-order perturbation terms in the ground state energy and chemical potential, and obtain simple…

Statistical Mechanics · Physics 2009-11-07 Hiroyuki Yoshimoto , Susumu Kurihara

By combining Hartree-Fock with a neural-network-supported quantum-cluster solver proposed recently in the context of solid-state lattice models, we formulate a scheme for selective neural-network configuration interaction (NNCI)…

We study several approaches to orbital optimization in selected configuration interaction plus perturbation theory (SCI+PT) methods, and test them on the ground and excited states of three molecules using the semistochastic heatbath…

Chemical Physics · Physics 2021-07-14 Yuan Yao , C. J. Umrigar

Over the course of the past few decades, the field of computational chemistry has managed to manifest itself as a key complement to more traditional lab-oriented chemistry. This is particularly true in the wake of the recent renaissance of…

Chemical Physics · Physics 2018-10-16 Janus J. Eriksen , Jürgen Gauss

A recent direction in quantum computing for molecular electronic structure sees the use of quantum devices as configuration sampling machines integrated within high-performance computing (HPC) platforms. This appeals to the strengths of…

Quantum Physics · Physics 2026-05-18 Tim Weaving , Angus Mingare , Alexis Ralli , Peter V. Coveney

We carefully study how the fermion-fermion interactions affect the low-energy states of a two-dimensional spin-$1/2$ fermionic system on the kagom\'{e} lattice with a quadratic band crossing point. With the help of the renormalization group…

Strongly Correlated Electrons · Physics 2021-04-07 Ya-Hui Zhai , Jing Wang

Asymptotics-based configuration-interaction (CI) methods [G. Friesecke and B. D. Goddard, Multiscale Model. Simul. 7, 1876 (2009)] are a class of CI methods for atoms which reproduce, at fixed finite subspace dimension, the exact…

Quantum Physics · Physics 2012-04-06 Christian Mendl , Gero Friesecke

We investigate the dynamics of spontaneous fission in a configuration-interaction (CI) approach. In that formalism the decay rate is governed by an effective interaction coupling the ground-state configuration and a fission doorway…

Nuclear Theory · Physics 2020-08-19 K. Hagino , G. F. Bertsch

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

Doubly occupied configuration interaction (DOCI), the exact diagonalization of the Hamiltonian in the paired (seniority zero) sector of the Hilbert space, is a combinatorial cost wave function that can be very efficiently approximated by…

Chemical Physics · Physics 2020-05-14 Jacob M. Wahlen-Strothman , Thomas M. Henderson , Gustavo E. Scuseria

Inspired by our earlier semi-stochastic work aimed at converging high-level coupled-cluster (CC) energetics [J. E. Deustua, J. Shen, and P. Piecuch, Phys. Rev. Lett. 119, 223003 (2017); J. Chem. Phys. 154, 124103 (2021)], we propose a novel…

Chemical Physics · Physics 2022-10-06 Karthik Gururangan , J. Emiliano Deustua , Jun Shen , Piotr Piecuch

Even when starting with a very poor initial guess, the iterative configuration interaction (iCI) approach can converge from above to full CI very quickly by constructing and diagonalizing a small Hamiltonian matrix at each…

Chemical Physics · Physics 2020-01-07 Ning Zhang , Wenjian Liu , Mark R. Hoffmann

Preparing the ground state of a given Hamiltonian and estimating its ground energy are important but computationally hard tasks. However, given some additional information, these problems can be solved efficiently on a quantum computer. We…

Quantum Physics · Physics 2020-12-16 Lin Lin , Yu Tong

Quantum computing promises to revolutionize many-body simulations for quantum chemistry, but its potential is constrained by limited qubits and noise in current devices. In this work, we introduce the Lossy Quantum Selected Configuration…

Quantum Physics · Physics 2025-09-17 Yu-cheng Chen , Ronin Wu , M. H. Cheng , Min-Hsiu Hsieh

We consider a two-component Fermi gas with a contact interaction from the BCS regime to the unitary limit. Starting from the idea that many-body effects should not depend on short-distance or high-momentum physics which is encoded in the…

Quantum Gases · Physics 2021-06-15 M. Urban , S. Ramanan

A coherent state technique is used to generate an Interacting Boson Model (IBM) Hamiltonian energy surface that simulates a mean field energy surface. The method presented here has some significant advantages over previous work.…

Nuclear Theory · Physics 2015-03-18 I. Bentley , S. Frauendorf