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Related papers: Geminal-Based Configuration Interaction

200 papers

The Projected Configuration Interaction (PCI) method starts from a collection of mean-field wave functions, and builds up correlated wave functions of good symmetry. It relies on the Generator Coordinator Method (GCM) techniques, but it…

Nuclear Theory · Physics 2009-02-18 Zaochun Gao , Mihai Horoi

We establish a new geometric wave function that combined with a variational principle efficiently describes a system of bosons interacting in a one-dimensional trap. By means of a a combination of the exact wave function solution for…

Quantum Gases · Physics 2014-04-03 B. Wilson , A. Foerster , C. C. N. Kuhn , I. Roditi , D. Rubeni

The configuration interaction (CI) is a versatile wavefunction theory for interacting fermions but it involves an extremely long CI series. Using a symmetric tensor decomposition (STD) method, we convert the CI series into a compact and…

Chemical Physics · Physics 2013-05-30 Wataru Uemura , Osamu Sugino

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

In previous research, we tested the wave function format of a linear combination of several antisymmetrized geminal power states. A numerical problem in the geminal matrices was noted, which made the total energies of electronic systems…

Chemical Physics · Physics 2019-02-06 Wataru Uemura , Takahito Nakajima

Diradical molecules are essential species involved in many organic and inorganic chemical reactions. The computational study of their electronic structure is often challenging, because a reliable description of the correlation, and in…

Chemical Physics · Physics 2014-06-18 Andrea Zen , Emanuele Coccia , Ye Luo , Sandro Sorella , Leonardo Guidoni

A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff $\Lambda$. These are constructed from a model space containing determinants with energy relative to that of the most stable…

Chemical Physics · Physics 2015-06-19 Francesco A. Evangelista

Traditional multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis (OB). For atoms with complicated shell structures, a large OB is needed to saturate all the…

Atomic Physics · Physics 2015-06-12 S. Verdebout , P. Rynkun , P. Jönsson , G. Gaigalas , C. Froese Fischer , M. Godefroid

The wide applications of Generative adversarial networks benefit from the successful training methods, guaranteeing that an object function converges to the local minima. Nevertheless, designing an efficient and competitive training method…

Machine Learning · Computer Science 2021-11-11 Huiqing Qi , Fang Li , Shengli Tan , Xiangyun Zhang

Mutual forces can be induced between coupled structures when illuminated by external acoustic waves. In this Letter, we propose a concept of asymmetric interaction between two coupled plate-like structures, which is generated by oppositely…

Classical Physics · Physics 2016-01-20 Xiying Fan , Chunyin Qiu , Shenwei Zhang , Manzhu Ke , Zhengyou Liu

Geminal wavefunctions have been employed to model strongly-correlated electrons. These wavefunctions represent products of weakly-correlated pairs of electrons and reasonable approximations are computable with polynomial cost. In…

The effect of the electron-electron cusp on the convergence of configuration interaction (CI) wave functions is examined. By analogy with the pseudopotential approach for electron-ion interactions, an effective electron-electron interaction…

Strongly Correlated Electrons · Physics 2009-11-07 David Prendergast , M. Nolan , Claudia Filippi , Stephen Fahy , J. C. Greer

We present a new geminal product wave function ansatz where the geminals are not constrained to be strongly orthogonal nor to be of seniority zero. Instead, we introduce weaker orthogonality constraints between geminals which significantly…

Chemical Physics · Physics 2023-01-09 Patrick Cassam-Chenaï , Thomas Perez , Davide Accomasso

We introduce a new procedure for iterative selection of determinant spaces capable of describing highly correlated systems. This adaptive configuration interaction (ACI) determines an optimal basis by an iterative procedure in which the…

Chemical Physics · Physics 2016-05-25 Jeffrey B. Schriber , Francesco A. Evangelista

Understanding superfluidity remains a major goal of condensed matter physics. Here we tackle this challenge utilizing the recently developed Fermionic neural network (FermiNet) wave function Ansatz [D. Pfau et al., Phys. Rev. Res. 2, 033429…

Selected configuration interaction (SCI) methods, when complemented with a second-order perturbative correction, provide near full configuration interaction (FCI) quality energies with only a small fraction of the Slater determinants of the…

A microscopic configuration-interaction (CI) methodology is introduced to enable bottom-up Schroedinger-equation emulation of unconventional superconductivity in ultracold optical traps. We illustrate the method by exploring the properties…

Quantum Gases · Physics 2017-05-24 Benedikt B. Brandt , Constantine Yannouleas , Uzi Landman

Scalar products and density matrix elements of closed-shell pair geminal wavefunctions are evaluated directly in terms of the pair amplitudes, resulting in an analogue of Wick's theorem for fermions or bosons. This expression is in general…

Chemical Physics · Physics 2022-06-15 Jean-David Moisset , Charles-Émile Fecteau , Paul A. Johnson

Wavefunctions restricted to electron-pair states are promising models to describe static/nondynamic electron correlation effects encountered, for instance, in bond-dissociation processes and transition-metal and actinide chemistry. To reach…

Chemical Physics · Physics 2017-01-18 Katharina Boguslawski , Paweł Tecmer

We introduce single and double particle-hole excitations in the recently revived spin-projected Hartree-Fock. Our motivation is to treat static correlation with spin-projection and recover the residual correlation, mostly dynamic in nature,…

Chemical Physics · Physics 2016-01-20 Takashi Tsuchimochi , Seiichiro Ten-no