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We introduce a differentiable clustering method based on stochastic perturbations of minimum-weight spanning forests. This allows us to include clustering in end-to-end trainable pipelines, with efficient gradients. We show that our method…

Machine Learning · Computer Science 2023-11-07 Lawrence Stewart , Francis S Bach , Felipe Llinares López , Quentin Berthet

We present a formulation of Laplace-transformed atomic orbital-based second-order M{\o}ller-Plesset perturbation theory (MP2) energies for two-component Hamiltonians in the Kramers-restricted formalism. This low-order scaling technique can…

Chemical Physics · Physics 2017-05-18 Benjamin Helmich-Paris , Michal Repisky , Lucas Visscher

We report in this paper an implementation of 4-component relativistic Hamiltonian based Equation-of-Motion Coupled-Cluster with singles and doubles (EOM-CCSD) theory for the calculation of ionization potential (IP), electron affinity (EA)…

Chemical Physics · Physics 2018-11-09 Avijit Shee , Trond Saue , Lucas Visscher , Andre Severo Pereira Gomes

Convex clustering, a convex relaxation of k-means clustering and hierarchical clustering, has drawn recent attentions since it nicely addresses the instability issue of traditional nonconvex clustering methods. Although its computational…

Methodology · Statistics 2019-01-01 Binhuan Wang , Yilong Zhang , Will Wei Sun , Yixin Fang

The development of multireference coupled cluster (MRCC) techniques has remained an open area of study in electronic structure theory for decades due to the inherent complexity of expressing a multi-configurational wavefunction in the…

Chemical Physics · Physics 2023-05-24 Maria-Andreea Filip , Alex J. W. Thom

We present a newly developed scheme for atomic relaxations of magnetic supported clusters. Our approach is based on the full potential Korringa-Kohn-Rostoker Green's function method and the second moment tight-binding approximation for…

Materials Science · Physics 2007-05-23 V. S. Stepanyuk , A. L. Klavsyuk , L. Niebergall , A. M. Saletsky , W. Hergert , P. Bruno

We develop a local correlation variant of auxiliary field quantum Monte Carlo (AFQMC) that is based on local natural orbitals (LNO-AFQMC). In LNO-AFQMC, independent AFQMC calculations are performed for each localized occupied orbital using…

Chemical Physics · Physics 2023-08-25 Jo S. Kurian , Hong-Zhou Ye , Ankit Mahajan , Timothy C. Berkelbach , Sandeep Sharma

We prove clustering estimates for the truncated correlations, i.e., cumulants of an unbounded spin system on the lattice. We provide a unified treatment, based on cluster expansion techniques, of four different regimes: large mass, small…

Mathematical Physics · Physics 2015-05-13 Abdelmalek Abdesselam , Aldo Procacci , Benedetto Scoppola

We propose a modified coupled cluster Monte Carlo algorithm that stochastically samples connected terms within the truncated Baker--Campbell--Hausdorff expansion of the similarity transformed Hamiltonian by construction of coupled cluster…

Chemical Physics · Physics 2019-06-19 Charles J. C. Scott , Roberto Di Remigio , T. Daniel Crawford , Alex J. W. Thom

Spin Hamiltonians, like the Heisenberg model, are used to describe magnetic properties of exchange-coupled molecules and solids. For finite clusters, physical quantities such as heat capacities, magnetic susceptibilities or…

Strongly Correlated Electrons · Physics 2025-06-24 Shadan Ghassemi Tabrizi , Thomas D. Kühne

We propose a multireference linearized coupled cluster theory using matrix product states (MPS-LCC) which provides remarkably accurate ground-state energies, at a computational cost that has the same scaling as multireference configuration…

Chemical Physics · Physics 2015-09-02 Sandeep Sharma , Ali Alavi

Dynamic tensor data are becoming prevalent in numerous applications. Existing tensor clustering methods either fail to account for the dynamic nature of the data, or are inapplicable to a general-order tensor. Also there is often a gap…

Machine Learning · Statistics 2018-09-17 Will Wei Sun , Lexin Li

We introduce an algorithm that is simultaneously memory-efficient and low-scaling for applying ab initio molecular Hamiltonians to matrix-product states (MPS) via the tensor-hypercontraction (THC) format. These gains carry over to Krylov…

Strongly Correlated Electrons · Physics 2025-11-19 Yu Wang , Maxine Luo , Matthias Reumann , Christian B. Mendl

This paper focuses on the sparse subspace clustering problem, and develops an online algorithmic solution to cluster data points on-the-fly, without revisiting the whole dataset. The strategy involves an online solution of a sparse…

Optimization and Control · Mathematics 2024-07-16 Liam Madden , Stephen Becker , Emiliano Dall'Anese

We present a new method for clustering based on compression. The method doesn't use subject-specific features or background knowledge, and works as follows: First, we determine a universal similarity distance, the normalized compression…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 Rudi Cilibrasi , Paul Vitanyi

Nonequilibrium dynamics of highly-controlled quantum systems is a challenging issue in statistical physics and quantum many-body physics, relevant to recent experimental developments of analog and digital quantum simulations. In this work,…

Quantum Gases · Physics 2025-05-21 Kazuma Nagao , Seiji Yunoki

The original formulation (Phys. Rev. Lett. 119, 063002, 2017) of the natural orbital functional - second-order M{\o}ller-Plesset (NOF-MP2) method is based on the MP2 that uses the canonical Hartree-Fock molecular orbitals. The current work…

Chemical Physics · Physics 2018-08-22 Mario Piris

The cluster reduction method for the Yakubovsky equations in configuration space is used for calculations of zero-energy scattering in four-nucleon system. The main idea of the method consists in making use of expansions for the Yakubovsky…

Nuclear Theory · Physics 2008-02-03 S. L. Yakovlev , I. N. Filikhin

The method of sub-iteration, which was previously applied to the higher-order coupled cluster amplitude equations, is extended to the case of the coupled cluster $\Lambda$ equations. The sub-iteration procedure for the $\Lambda$ equations…

Chemical Physics · Physics 2025-03-26 Devin A. Matthews

We report an approach for determination of zero-field splitting parameters from four-component relativistic calculations. Our approach involves neither perturbative treatment of spin-orbit interaction nor truncation of the spin-orbit…

Chemical Physics · Physics 2019-03-26 Ryan D. Reynolds , Toru Shiozaki