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Related papers: Reduced Scaling Real-Time Coupled Cluster Theory

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Recently, several claims have been made that certain fundamental problems of distributed computing, including Leader Election and Distributed Consensus, begin to admit feasible and efficient solutions when the model of distributed…

Quantum Physics · Physics 2009-03-09 Cyril Gavoille , Adrian Kosowski , Marcin Markiewicz

This paper analyzes general spatially-coupled (SC) systems with multi-dimensional coupling. A continuum approximation is used to derive potential functions that characterize the performance of the SC systems. For any dimension of coupling,…

Information Theory · Computer Science 2013-04-19 Keigo Takeuchi , Toshiyuki Tanaka , Kenta Kasai

We introduce a range-separation approximation to coupled cluster doubles (CCD) theory that successfully overcomes limitations of regular CCD when applied to the uniform electron gas. We combine the short-range ladder channel with the…

Chemical Physics · Physics 2014-05-07 James J. Shepherd , Thomas M. Henderson , Gustavo E. Scuseria

Spectral clustering is a novel clustering method which can detect complex shapes of data clusters. However, it requires the eigen decomposition of the graph Laplacian matrix, which is proportion to $O(n^3)$ and thus is not suitable for…

Machine Learning · Computer Science 2013-07-02 Nguyen Lu Dang Khoa , Sanjay Chawla

We develop a static quantum embedding scheme that utilizes different levels of approximations to coupled cluster (CC) theory for an active fragment region and its environment. To reduce the computational cost, we solve the local fragment…

Chemical Physics · Physics 2024-11-13 Avijit Shee , Fabian M. Faulstich , Birgitta Whaley , Lin Lin , Martin Head-Gordon

We consider a new formulation of the stochastic coupled cluster method in terms of the similarity transformed Hamiltonian. We show that improvement in the granularity with which the wavefunction is represented results in a reduction in the…

Chemical Physics · Physics 2016-02-02 Ruth S. T. Franklin , James S. Spencer , Alberto Zoccante , Alex J. W. Thom

Given a graph with positive and negative edge labels, the correlation clustering problem aims to cluster the nodes so to minimize the total number of between-cluster positive and within-cluster negative edges. This problem has many…

Data Structures and Algorithms · Computer Science 2024-06-17 Mina Dalirrooyfard , Konstantin Makarychev , Slobodan Mitrović

The recent quantum information boom has effected a resurgence of interest in unitary coupled cluster (UCC) theory. Our group's interest in local energy landscapes of unitary ans\"atze prompted us to investigate the classical approach of…

Chemical Physics · Physics 2022-11-01 Harper R. Grimsley , Nicholas J. Mayhall

We introduce a novel class of coupled cluster (CC) methods that leverage the seniority concept to enhance efficiency and accuracy in electronic structure calculations. While existing approaches, such as the pair coupled cluster doubles…

While limited coupled cluster theory is \textit{formally} nonvariational, it is not broadly appreciated whether this is a major issue \textit{in practice}. We carried out a detailed comparison with \textit{de facto} full CI energies for a…

Chemical Physics · Physics 2024-10-03 Jan M. L. Martin , Emmanouil Semidalas

The recently introduced coupled cluster (CC) downfolding techniques for reducing the dimensionality of quantum many-body problems recast the CC formalism in the form of the renormalization procedure allowing, for the construction of…

Quantum Physics · Physics 2021-11-08 Nicholas P. Bauman , Karol Kowalski

Unsupervised clustering of temporal data is both challenging and crucial in machine learning. In this paper, we show that neither traditional clustering methods, time series specific or even deep learning-based alternatives generalise well…

Machine Learning · Computer Science 2020-10-13 Nuno Mota Goncalves , Ioana Giurgiu , Anika Schumann

A dynamical formulation of coupled cluster theory is derived using a variational principle. By allowing time-dependent single-particle functions, a high degree of adaptivity is introduced, allowing complex systems to be simulated with high…

Quantum Physics · Physics 2014-11-25 Simen Kvaal

We present a principled spectral approach to the well-studied constrained clustering problem. It reduces clustering to a generalized eigenvalue problem on Laplacians. The method works in nearly-linear time and provides concrete guarantees…

Social and Information Networks · Computer Science 2016-01-20 Mihai Cucuringu , Ioannis Koutis , Sanjay Chawla

Spectral clustering techniques are valuable tools in signal processing and machine learning for partitioning complex data sets. The effectiveness of spectral clustering stems from constructing a non-linear embedding based on creating a…

Machine Learning · Computer Science 2021-02-02 Farhad Pourkamali-Anaraki

In the molecular quantum chemistry community, coupled-cluster (CC) methods are well-recognized for their systematic convergence and reliability. The extension of the theory to extended systems has been comparably recent, so that…

Chemical Physics · Physics 2024-10-31 Andreas Grüneis , Evgeny Moerman , Matthias Scheffler , Tonghao Shen , Igor Ying Zhang

The time-dependent equation-of-motion coupled cluster (TD-EOM-CC) and time-dependent coupled cluster (TDCC) methods are compared by simulating Rabi oscillations for different numbers of non-interacting atoms in a classical electromagnetic…

Chemical Physics · Physics 2023-10-02 Andreas S. Skeidsvoll , Henrik Koch

This paper presents Constrained Centroid Clustering (CCC), a method that extends classical centroid-based clustering by enforcing a constraint on the maximum distance between the cluster center and the farthest point in the cluster. Using a…

Machine Learning · Computer Science 2025-08-19 Sowmini Devi Veeramachaneni , Ramamurthy Garimella

Temporal data, obtained in the setting where it is only possible to observe one time point per experiment, is widely used in different research fields, yet remains insufficiently addressed from the statistical point of view. Such data often…

Methodology · Statistics 2025-03-10 Polina Arsenteva , Mohamed Amine Benadjaoud , Hervé Cardot

Many appplications in computational science are sufficiently compute-intensive that they depend on the power of parallel computing for viability. For all but the "embarrassingly parallel" problems, the performance depends upon the level of…

High Energy Physics - Lattice · Physics 2009-09-29 Z. Sroczynski , N. Eicker , Th. Lippert , B. Orth , K. Schilling