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Related papers: A Neural-Network-Based Selective Configuration Int…

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We present the quantum-selected configuration interaction-tailored coupled-cluster (QSCI-TCC) method, a hybrid quantum-classical scheme that tailors coupled-cluster (CC) theory with a quantum-selected configuration interaction (QSCI) wave…

Chemical Physics · Physics 2025-06-23 Luca Erhart , Yuichiro Yoshida , Wataru Mizukami

Although selected configuration interaction (SCI) algorithms can tackle much larger Hilbert spaces than the conventional full CI (FCI) method, the scaling of their computational cost with respect to the system size remains inherently…

Chemical Physics · Physics 2024-12-02 Abdallah Ammar , Anthony Scemama , Pierre-François Loos , Emmanuel Giner

We present a quantum algorithm for the simulation of molecular systems that is asymptotically more efficient than all previous algorithms in the literature in terms of the main problem parameters. As in previous work [Babbush et al., New…

The nucleon-pair approximation (NPA) can be a compact alternative to full configuration-interaction (FCI) diagonalization in nuclear shell-model spaces, but selecting good pairs is a long-standing problem. While seniority-based pairs work…

Nuclear Theory · Physics 2020-08-25 G. J. Fu , Calvin W. Johnson

We investigate the existence of holomorphic Hartree-Fock solutions using a revised SCF algorithm. We use this algorithm to study the Hartree-Fock solutions for H$_{2}$ and H$_{4}^{2+}$ and report the emergence of holomorphic solutions at…

Chemical Physics · Physics 2015-11-20 Hugh G. A. Burton , Alex J. W. Thom

Silicon quantum computing has the potential to revolutionize technology with capabilities to solve real-life problems that are computationally complex or even intractable for modern computers [1] by offering sufficient high quality qubits…

Mesoscale and Nanoscale Physics · Physics 2024-09-24 Dylan H. Liang , MengKe Feng , Philip Y. Mai , Jesus D. Cifuentes , Andrew S. Dzurak , Andre Saraiva

We present a new method for the optimization of large configuration interaction (CI) expansions in the quantum Monte Carlo (QMC) framework. The central idea here is to replace the non-orthogonal variational optimization of CI coefficients…

Chemical Physics · Physics 2022-05-26 Abdallah Ammar , Emmanuel Giner , Anthony Scemama

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

The multi-configuration Dirac-Hartree-Fock method was employed to calculate the total and excitation energies, oscillator strengths and hyperfine structure constants for low-lying levels of Sm I. In the first-order perturbation…

Atomic Physics · Physics 2015-09-16 Fuyang Zhou , Yizhi Qu , Jiguang Li , Jianguo Wang

We present a density matrix approach for computing global solutions of Hartree-Fock theory, based on semidefinite programming (SDP), that gives upper and lower bounds on the Hartree-Fock energy of quantum systems. Equality of the upper- and…

Chemical Physics · Physics 2014-02-11 Srikant Veeraraghavan , David A. Mazziotti

Quantum-selected configuration interaction (QSCI) is a promising hybrid quantum-classical approach in which a quantum device generates configurations for subsequent classical diagonalization. Here, we analyze the performance of QSCI…

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

We report internally contracted relativistic multireference configuration interaction (ic-MRCI), complete active space second-order perturbation (CASPT2), and strongly contracted n-electron valence state perturbation theory (NEVPT2) on the…

Chemical Physics · Physics 2015-12-31 Toru Shiozaki , Wataru Mizukami

The ground state of second-quantized quantum chemistry Hamiltonians provides access to an important set of chemical properties. Wavefunctions based on ML architectures have shown promise in approximating these ground states in a variety of…

Chemical Physics · Physics 2024-11-04 An-Jun Liu , Bryan K. Clark

The Hartree-Fock based diagonalization is a computational method for the investigation of the low-energy properties of correlated electrons in disordered solids. The method is related to the quantum-chemical configuration interaction…

Disordered Systems and Neural Networks · Physics 2007-05-23 Michael Schreiber , Thomas Vojta

We propose a general framework to extract microscopic interactions from raw configurations with deep neural networks. The approach replaces the modeling Hamiltonian by the neural networks, in which the interaction is encoded. It can be…

Computational Physics · Physics 2020-08-19 Lingxiao Wang , Yin Jiang , Kai Zhou

The efficiency of the recently proposed iCIPT2 [iterative configuration interaction (iCI) with selection and second-order perturbation theory (PT2); J. Chem. Theory Comput. 16, 2296 (2020)] for strongly correlated electrons is further…

Chemical Physics · Physics 2020-11-19 Ning Zhang , Wenjian Liu , Mark R. Hoffmann

The symmetry-projected Hartree--Fock ansatz for the electronic structure problem can efficiently account for static correlation in molecules, yet it is often unable to describe dynamic correlation in a balanced manner. Here, we consider a…

Strongly Correlated Electrons · Physics 2015-06-17 Carlos A. Jiménez-Hoyos , R. Rodríguez-Guzmán , Gustavo E. Scuseria

A new electronic structure model is developed in which the ground state energy of a molecular system is given by a Hartree-Fock-like expression with parametrized one- and two-electron integrals over an extended (minimal + polarization) set…

Chemical Physics · Physics 2014-02-11 Dimitri N. Laikov

We present an implementation of the multiconfiguration time-dependent Hartree-Fock method based on the adaptive finite element method for molecules under intense laser pulses. For efficient simulations, orbital functions are propagated by a…

Quantum Physics · Physics 2023-01-09 Yuki Orimo , Takeshi Sato , Kenichi L. Ishikawa