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We investigate the performance of a class of compact and systematically improvable Jastrow-Slater wave functions for the efficient and accurate computation of structural properties, where the determinantal component is expanded with a…

Chemical Physics · Physics 2019-01-17 Monika Dash , Saverio Moroni , Anthony Scemama , Claudia Filippi

Pair atomic density fitting (PADF) is a promising strategy to reduce the scaling with system size of quantum chemical methods for the calculation of the correlation energy like the direct random phase approximation (RPA) or second-order…

Chemical Physics · Physics 2023-03-14 Edoardo Spadetto , Pier Herman Theodoor Philipsen , Arno Förster , Lucas Visscher

The adaptively compressed exchange (ACE) method provides an efficient way for solving Hartree-Fock-like equations in quantum physics, chemistry, and materials science. The key step of the ACE method is to adaptively compress an operator…

Numerical Analysis · Mathematics 2017-11-22 Lin Lin , Michael Lindsey

A simple and commonly employed approximate technique with which one can examine spatially disordered systems when strong electronic correlations are present is based on the use of real-space unrestricted self-consistent Hartree-Fock wave…

Strongly Correlated Electrons · Physics 2009-11-13 X. Chen , A. Farhoodfar , T. McIntosh , R. J. Gooding , P. W. Leung

The Configuration Interaction (CI) method using orbitals centered on the nucleus has recently been applied to calculate the interactions of positrons interacting with atoms. Computational investigations of the convergence properties of…

Atomic Physics · Physics 2007-05-23 J. Mitroy , M. W. J. Bromley

The time-dependent multiconfiguration self-consistent-field method based on the occupation-restricted multiple active space model is proposed (TD-ORMAS) for multielectron dynamics in intense laser fields. Extending the previously proposed…

Atomic Physics · Physics 2015-06-23 Takeshi Sato , Kenichi L. Ishikawa

A method for increasing the accuracy of configuration interaction (CI) calculations of molecules and other electronic systems is proposed. The energy defect of a given calculation is associated with the electron pair origin of…

Chemical Physics · Physics 2025-11-18 Jerry L. Whitten

In this paper we present a computational procedure that utilizes real-space grids to obtain high precision approximations of electrostatically confined few-electron states such as those that arise in gated semiconductor quantum dots. We use…

Mesoscale and Nanoscale Physics · Physics 2023-01-27 Christopher R. Anderson , Mark F. Gyure , Sam Quinn , Andrew Pan , Richard S. Ross , Andrey A. Kiselev

Electronic resonances are metastable states that can decay by electron loss. They are ubiquitous across various fields of science, such as chemistry, physics, and biology. However, current theoretical and computational models for resonances…

Chemical Physics · Physics 2025-04-15 Yann Damour , Anthony Scemama , Fábris Kossoski , Pierre-François Loos

The configuration interaction relativistic Hartree-Fock (CI-RHF) model is developed in this work. Compared to the conventional configuration interaction shell model (CISM), the CI-RHF model can be applied to study the structural properties…

Nuclear Theory · Physics 2025-04-14 Jia Liu , Yi Fei Niu , Wen Hui Long

It has recently been shown that configuration state functions (CSF) with local orbitals can provide a compact reference state for low-spin open-shell electronic structures, such as antiferromagnetic states. However, optimizing a low-spin…

Chemical Physics · Physics 2025-08-05 Hugh G. A. Burton

Modern quantum Monte Carlo (QMC) methods often capture electron correlation through both explicitly correlating Jastrow factors and small to mid-sized configuration interaction (CI) expansions. Here, we study the additional optimization…

Chemical Physics · Physics 2023-02-08 Scott M. Garner , Eric Neuscamman

Spin plays a fundamental role in understanding electronic structure, yet many real-space wavefunction methods fail to adequately consider it. We introduce the Spin-Adapted Antisymmetrization Method (SAAM), a general procedure that enforces…

Chemical Physics · Physics 2025-11-04 Ruichen Li , Yuzhi Liu , Du Jiang , Yixiao Chen , Xuelan Wen , Wenrui Li , Di He , Liwei Wang , Ji Chen , Weiluo Ren

A Monte Carlo method for evaluating multi-center two-electron-repulsion integrals over any type of orbitals (Slater, Sturmian, finite-range, numerical, etc.) is presented. The approach is based on a simple and universal…

Chemical Physics · Physics 2019-09-04 Michel Caffarel

We present unrestricted Hartree Fock method coupled with configuration interaction (CI) method (URHF-CI) suitable for the calculation of ground and excited states of large number of electrons localized by complex gate potentials in…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ramin M. Abolfath , Pawel Hawrylak

We describe the time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method for a system of interacting bosons. We provide the theory of the method and discuss its numerical implementation. The method provides a general…

Quantum Physics · Physics 2017-04-28 Camille Lévêque , Lars Bojer Madsen

An adaptation of the full configuration interaction quantum Monte Carlo (FCIQMC) method is presented, for correlated electron problems containing heavy elements and the presence of significant relativistic effects. The modified algorithm…

Chemical Physics · Physics 2020-10-26 Robert J. Anderson , George H. Booth

We present a quantum-classical hybrid algorithm for calculating the ground state and its energy of the quantum many-body Hamiltonian by proposing an adaptive construction of a quantum state for the quantum-selected configuration interaction…

Quantum Physics · Physics 2024-12-12 Yuya O. Nakagawa , Masahiko Kamoshita , Wataru Mizukami , Shotaro Sudo , Yu-ya Ohnishi

We present low-scaling algorithms for $GW$ and constrained random phase approximation based on a symmetry-adapted interpolative separable density fitting (ISDF) procedure that incorporates the space-group symmetries of crystalline systems.…

Materials Science · Physics 2024-01-24 Chia-Nan Yeh , Miguel A. Morales

Most nonrelativistic electron correlation methods can be adapted to account for relativistic effects, as long as the relativistic molecular spinor integrals are available, from either a four-, two-, or one-component mean-field calculation.…

Strongly Correlated Electrons · Physics 2024-07-17 Zijun Zhao , Francesco A. Evangelista