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Related papers: A Perturbative Super-CI Approach for orbital optim…

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A general-order open-shell coupled-cluster method based on spatial orbitals is formulated. The method is an extension of the partial-spin adaptation (PSA) scheme from Janssen and Schaefer (Theor. Chim. Acta, 79, 1-42, 1991). By increasing…

Chemical Physics · Physics 2024-03-18 Cong Wang

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

We study the mechanism of orbital/spin fluctuations due to multiorbital Coulomb interaction in iron-based superconductors, going beyond the random-phase-approximation. For this purpose, we develop a self-consistent vertex correction (SC-VC)…

Superconductivity · Physics 2012-09-26 Seiichiro Onari , Hiroshi Kontani

Unitary Coupled Cluster (UCC) theory is a promising variational method for electronic structure calculations, especially for strongly correlated systems and quantum computers. However, its practical application is limited by the steep…

Chemical Physics · Physics 2026-02-05 Prateek Vaish , Brenda Rubenstein

We introduce two new methods for deterministic convex optimization problems: QCC (Quadratic Cuts for Convex optimization) and QB (Quadratic Bundle method). We prove the complexity of these methods for composite optimization problems which…

Optimization and Control · Mathematics 2024-10-02 Vincent Guigues , Adriana Washington

Besides tensor contractions, one of the most pronounced computational bottlenecks in the non-orthogonally spin-adapted forms of the quantum chemistry methods CCSDT and CCSDTQ, and their approximate forms---including CCSD(T) and…

Mathematical Software · Computer Science 2017-05-19 Paul Springer , Devin Matthews , Paolo Bientinesi

Hybrid spin-mechanical systems provide a platform for integrating quantum registers and transducers. Efficient creation and control of such systems require a comprehensive understanding of the individual spin and mechanical components as…

Measuring the magnetoresistance (MR) of ultraclean {\it GaAs} two-dimensional holes in a large $r_s$ range of 20-50, two striking behaviors in relation to the spin-orbit coupling (SOC) emerge in response to strong electron-electron…

Strongly Correlated Electrons · Physics 2017-06-02 Jian Huang , L. N. Pfeiffer , K. W. West

Consider the stochastic composition optimization problem where the objective is a composition of two expected-value functions. We propose a new stochastic first-order method, namely the accelerated stochastic compositional proximal gradient…

Optimization and Control · Mathematics 2016-07-26 Mengdi Wang , Ji Liu , Ethan X. Fang

We describe the treatment of Rashba spin-orbit coupling (SOC) in interacting many-fermion systems within the auxiliary-field quantum Monte Carlo framework, and present a set of illustrative results. These include numerically exact…

Strongly Correlated Electrons · Physics 2019-06-10 Peter Rosenberg , Hao Shi , Shiwei Zhang

The spontaneous dimerization of the frustrated spin-$1\over2$ antiferromagnetic chains is studied by a microscopic approach based on a proper set of composite operators (i.e., pseudo-spin operators). Two approximation schemes are developed.…

Condensed Matter · Physics 2009-10-22 Yang Xian

We report the formulation of a new, cost-effective approximation method in the time-dependent optimized coupled-cluster (TD-OCC) framework [T. Sato et al., J. Chem. Phys. 148, 051101 (2018)] for first-principles simulations of multielectron…

Chemical Physics · Physics 2022-08-11 Himadri Pathak , Takeshi Sato , Kenichi L. Ishikawa

Interatomic hopping mediated by spin-orbit coupling (SOC) entangles spin, orbital and sublattice degrees of freedom of electrons, leading to the emergence of intriguing phenomena such as novel topological insulators and exotic…

Materials Science · Physics 2024-07-16 Masaki Kato , Masao Ogata

In electronic structure theory, restricted single-reference coupled cluster (CC) captures weak correlation but fails catastrophically under strong correlation. Spin-projected unrestricted Hartree-Fock (SUHF), on the other hand, misses weak…

Chemical Physics · Physics 2017-11-22 John A. Gomez , Thomas M. Henderson , Gustavo E. Scuseria

There is a growing need for new optimization methods to facilitate the reliable and cost-effective operation of power systems with intermittent renewable energy resources. In this paper, we formulate the robust AC optimal power flow…

Optimization and Control · Mathematics 2018-04-03 Raphael Louca , Eilyan Bitar

Modern challenges arising in the fields of theoretical and experimental physics require new powerful tools for high-precision electronic structure modelling; one of the most perspective tools is the relativistic Fock space coupled cluster…

Computational Physics · Physics 2020-12-08 Alexander V. Oleynichenko , Andréi Zaitsevskii , Ephraim Eliav

The generalized relativistic effective core potential (GRECP) approach is employed in the framework of multireference single- and double-excitation configuration interaction (MRD-CI) method to calculate the spin-orbit (SO) splitting in the…

Chemical Physics · Physics 2007-05-23 A. V. Titov , N. S. Mosyagin , A. B. Alekseyev , R. J. Buenker

Orbital-free density functional theory as an extension of traditional Thomas-Fermi theory has attracted a lot of interest in the past decade because of developments in both more accurate kinetic energy functionals and highly efficient…

Materials Science · Physics 2009-11-10 Hong Jiang , Weitao Yang

We introduce a quadratically-constrained approximation (QCAC) of the AC optimal power flow (AC-OPF) problem. Unlike existing approximations like the DC-OPF, our model does not rely on typical assumptions such as high reactance-to-resistance…

Optimization and Control · Mathematics 2026-01-21 Gonzalo E. Constante-Flores , Can Li

While configuration interaction singles (CIS) provides a computationally efficient description of excited states, it systematically overestimates excitation energies and performs poorly for strongly correlated systems, partly due to the…

Chemical Physics · Physics 2026-04-01 Takashi Tsuchimochi , Benjamin Mokhtar
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