English
Related papers

Related papers: Infinite-order diagrammatic summation approach to …

200 papers

The most efficient known quantum circuits for preparing unitary coupled cluster states and applying Trotter steps of the arbitrary basis electronic structure Hamiltonian involve interleaved sequences of fermionic Gaussian circuits and Ising…

Quantum Physics · Physics 2021-09-13 Nicholas C. Rubin , Joonho Lee , Ryan Babbush

In this work, we investigate the possibility of improving multireference-driven coupled cluster (CC) approaches with an algorithm that iteratively combines complete active space (CAS) calculations with tailored CC and externally corrected…

Chemical Physics · Physics 2025-03-06 Robin Feldmann , Max Mörchen , Jakub Lang , Michał Lesiuk , Markus Reiher

Chemical short-range order (SRO) provides new opportunities for tuning alloy properties, but conventional computational thermodynamics frameworks such as CALPHAD, based on Bragg-Williams mean-field approximations, cannot properly describe…

Materials Science · Physics 2025-08-12 Chuliang Fu

We extend the recently proposed heat-bath configuration interaction (HCI) method [Holmes, Tubman, Umrigar, J. Chem. Theory Comput. 12, 3674 (2016)], by introducing a semistochastic algorithm for performing multireference Epstein-Nesbet…

Chemical Physics · Physics 2017-03-20 Sandeep Sharma , Adam Holmes , Guillaume Jeanmairet , Ali Alavi , C. J. Umrigar

A resolution of the identity due to canonical coherent states is often proven in the weak operator topology. However, such a resolution with an integral symbol is typically supposed to hold in the strong operator topology associated with…

Quantum Physics · Physics 2024-02-14 Ryo Namiki

The method of geometric harmonics is adapted to the situation of incomplete data by means of the iterated geometric harmonics (IGH) scheme. The method is tested on natural and synthetic data sets with 50--500 data points and dimensionality…

Machine Learning · Computer Science 2014-11-05 Chad Eckman , Jonathan A. Lindgren , Erin P. J. Pearse , David J. Sacco , Zachariah Zhang

In this work, we present a new diagrammatic method for computing the effective Hamiltonian of driven nonlinear oscillators. At the heart of our method is a self-consistent perturbation expansion developed in phase space, which establishes a…

Orbital optimization procedure is widely called in electronic structure simulation. To efficiently find the orbital optimization solution, we developed a new second order orbital optimization algorithm, co-iteration augmented Hessian (CIAH)…

Chemical Physics · Physics 2017-01-11 Qiming Sun

We consider an 1D partial integro-differential equation (PIDE) comprising of an 1D parabolic partial differential equation (PDE) and a nonlocal integral term. The control input is applied on one of the boundaries of the PIDE. Partitioning…

Systems and Control · Electrical Eng. & Systems 2025-09-26 Soham Chatterjee , Vivek Natarajan

We present a new approach based on real time domain Feynman path integrals (RTPI) for electronic structure calculations and quantum dynamics, which includes correlations between particles exactly but within the numerical accuracy. We…

Quantum Physics · Physics 2015-10-09 Ilkka Ruokosenmäki , Hosein Gholizade , Ilkka Kylänpää , Tapio T. Rantala

Explicitly-correlated F12 methods are becoming the first choice for high-accuracy molecular orbital calculations, and can often achieve chemical accuracy with relatively small gaussian basis sets. In most calculations, the many three- and…

Chemical Physics · Physics 2016-05-25 Giuseppe M. J. Barca , Pierre-François Loos , Peter M. W. Gill

The combinatorial scaling of configuration interaction (CI) has long restricted its applicability to only the simplest molecular systems. Here, we report the first numerically exact CI calculation exceeding one quadrillion ($10^{15}$)…

Chemical Physics · Physics 2025-12-16 Agam Shayit , Can Liao , Shiv Upadhyay , Hang Hu , Tianyuan Zhang , Eugene DePrince , Chao Yang , Xiaosong Li

An efficient approach to calculate approximate pure-state and transition reduced density matrices in the framework of the multireference relativistic Fock-space coupled cluster (FS CC) theory is proposed. The method is based on the…

Computational Physics · Physics 2025-06-12 Alexander V. Oleynichenko , Andrei Zaitsevskii , Leonid V. Skripnikov , Ephraim Eliav

NISQ era devices suffer from a number of challenges like limited qubit connectivity, short coherence times and sizable gate error rates. Thus, quantum algorithms are desired that require shallow circuit depths and low qubit counts to take…

This article presents novel numerical algorithms based on pseudodifferential operators for fast, direct, solution of the Helmholtz equation in 1D, 2D, and 3D inhomogeneous unbounded media. The proposed approach relies on an Operator Fourier…

Numerical Analysis · Mathematics 2024-10-22 Max Cubillos , Edwin Jimenez

Hybrid density functional theory (DFT) remains intractable for large periodic systems due to the demanding computational cost of exact exchange. We apply the tensor hypercontraction (THC) (or interpolative separable density fitting)…

Computational Physics · Physics 2023-10-13 Adam Rettig , Joonho Lee , Martin Head-Gordon

Most existing Re-IDentification (Re-ID) methods are highly dependent on precise bounding boxes that enable images to be aligned with each other. However, due to the challenging practical scenarios, current detection models often produce…

Computer Vision and Pattern Recognition · Computer Science 2019-05-07 Feng Zheng , Cheng Deng , Xing Sun , Xinyang Jiang , Xiaowei Guo , Zongqiao Yu , Feiyue Huang , Rongrong Ji

In the present work, an attempted was made to develop a numerical algorithm by the use of new orthogonal hybrid functions formed from hybrid of piecewise constant orthogonal sample-and-hold functions and piecewise linear orthogonal…

Numerical Analysis · Mathematics 2018-01-23 Seshu Kumar Damarla , Madhusree Kundu

The Kirchhoff plate model plays a vital role in modeling, computing and analyzing the mechanical behaviors of thin plate structures. This study propose a novel fourth-order multi-scale (FOMS) computational method for high-accuracy and…

Numerical Analysis · Mathematics 2025-12-10 Hao Dong , Liqun Cao

This work introduces and rigorously analyzes a novel operator-splitting finite element scheme for approximating viscosity solutions of a broad class of constrained second-order partial differential equations. By decoupling the primary PDE…

Numerical Analysis · Mathematics 2025-07-01 Po-Yi Wu