English
Related papers

Related papers: Aufbau suppressed coupled cluster as a post-linear…

200 papers

Subspace clustering is an unsupervised clustering technique designed to cluster data that is supported on a union of linear subspaces, with each subspace defining a cluster with dimension lower than the ambient space. Many existing…

Machine Learning · Computer Science 2021-03-23 Benjamin D. Haeffele , Chong You , René Vidal

An efficiency of the Tucker decomposition of amplitude tensors within the single-reference relativistic coupled cluster method with single and double excitations (RCCSD) was studied in a series of benchmark calculations for (AuCl)$_n$…

Computational Physics · Physics 2025-07-29 Alexander V. Oleynichenko , Artem S. Rumiantsev , Andrei Zaitsevskii , Ephraim Eliav

We tabulate angularly reduced fourth-order many-body corrections to matrix elements for univalent atoms, derived in [A. Derevianko and E.D. Emmons, Phys. Rev. A 65, 052115 (2002)]. In particular we focused on practically important diagrams…

Atomic Physics · Physics 2007-05-23 Andrei Derevianko

In a series of two articles, we propose a comprehensive mathematical framework for Coupled-Cluster-type methods. In this second part, we analyze the nonlinear equations of the single-reference Coupled-Cluster method using topological degree…

Numerical Analysis · Mathematics 2023-03-28 Mihály A. Csirik , Andre Laestadius

We present a novel approach to spin-adapted coupled cluster theory. This approach is based on the entanglement of an open-shell molecule with electrons in a non-interacting bath; together they form a closed-shell state. For the total…

Chemical Physics · Physics 2023-05-22 Sarai Dery Folkestad , Bendik Støa Sannes , Henrik Koch

Linear Programming (LP) relaxations have become powerful tools for finding the most probable (MAP) configuration in graphical models. These relaxations can be solved efficiently using message-passing algorithms such as belief propagation…

Data Structures and Algorithms · Computer Science 2012-06-18 David Sontag , Talya Meltzer , Amir Globerson , Tommi S. Jaakkola , Yair Weiss

Because all stars contribute to its gravitational potential, stellar clusters amplify perturbations collectively. In the limit of small fluctuations, this is described through linear response theory, via the so-called response matrix. While…

Astrophysics of Galaxies · Physics 2021-10-27 Jean-Baptiste Fouvry , Simon Prunet

The problem of orbital relaxation in computational core-hole spectroscopies, including x-ray absorption and x-ray photoionization, has long plagued linear response approaches, including equation-of-motion coupled cluster with singles and…

Chemical Physics · Physics 2025-03-26 Megan E. Simons , Devin A. Matthews

We derive and implement a new way of solving coupled cluster equations with lower computational scaling. Our method is based on decomposition of both amplitudes and two electron integrals, using a combination of tensor hypercontraction and…

Chemical Physics · Physics 2020-05-14 Roman Schutski , Jinmo Zhao , Thomas M. Henderson , Gustavo E. Scuseria

In this paper, a model reduction procedure for a network of interconnected identical passive subsystems is presented. Here, rather than performing model reduction on the subsystems, adjacent subsystems are clustered, leading to a…

Systems and Control · Computer Science 2014-04-29 Bart Besselink , Henrik Sandberg , Karl Henrik Johansson

While providing a highly accurate framework for simulating laser-induced many-electron dynamics in atom and molecules, including linear and nonlinear steady-state and transient absorption spectra, time-dependent coupled-cluster theory does…

Asymptotic post-buckling theory is applied to sizing and topology optimization of trusses and frames, exploring its potential and current computational difficulties. We show that a designs' post-buckling response can be controlled by…

Computational Engineering, Finance, and Science · Computer Science 2025-05-15 Federico Ferrari , Ole Sigmund

Quantum cluster theories are a set of approaches for the theory of correlated and disordered lattice systems, which treat correlations within the cluster explicitly, and correlations at longer length scales either perturbatively or within a…

Superconductivity · Physics 2009-11-11 T. A. Maier , M. S. Jarrell , D. J. Scalapino

We reveal limitations of several standard coupled-cluster (CC) methods with perturbation-theorybased noniterative or approximate iterative treatments of triple excitations when applied to thedetermination of highly accurate potential energy…

Chemical Physics · Physics 2021-10-04 Jan Schnabel , Lan Cheng , Andreas Köhn

The coupled cluster iteration scheme is analysed as a multivariate discrete-time map using nonlinear dynamics and synergetics. The nonlinearly coupled set of equations to determine the cluster amplitudes are driven by a fraction of the…

Computational Physics · Physics 2021-10-13 Valay Agarawal , Chayan Patra , Rahul Maitra

We present a spin-adapted time-dependent coupled cluster singles and doubles model for the molecular response to a sequence of ultrashort laser pulses. The implementation is used to calculate the electronic response to a valence-exciting…

Chemical Physics · Physics 2020-08-28 Andreas S. Skeidsvoll , Alice Balbi , Henrik Koch

Coupled cluster theory produced arguably the most widely used high-accuracy computational quantum chemistry methods. Despite the approach's overall great computational success, its mathematical understanding is so far limited to results…

Algebraic Geometry · Mathematics 2024-03-29 Fabian M. Faulstich , Mathias Oster

In this work, we derive working equations for the Linear Response pair Coupled Cluster Doubles (LR-pCCD) ansatz and its extension to singles (S), LR-pCCD+S. These methods allow us to compute electronic excitation energies and transition…

Chemical Physics · Physics 2025-03-18 Somayeh Ahmadkhani , Katharina Boguslawsk , Paweł Tecmer

To solve the relativistic bound-state problem one needs to systematically and simultaneously decouple the high-energy from the low-energy modes and the many-body from the few-particle states using a consistent renormalization scheme. In a…

High Energy Physics - Theory · Physics 2009-11-10 Amir H. Rezaeian , Niels R. Walet

In this paper, we have developed a unitary variant of a double exponential coupled cluster theory, which is capable of mimicking the effects of connected excitations of arbitrarily high rank, using only rank-one and rank-two parametrization…

Chemical Physics · Physics 2022-11-23 Dipanjali Halder , V. S. Prasannaa , Rahul Maitra