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Variational quantum eigensolvers (VQE) are among the most promising approaches for solving electronic structure problems on near-term quantum computers. A critical challenge for VQE in practice is that one needs to strike a balance between…

The computational expense of solving non-equilibrium chemistry equations in astrophysical simulations poses a significant challenge, particularly in high-resolution, large-scale cosmological models. In this work, we explore the potential of…

Instrumentation and Methods for Astrophysics · Physics 2025-07-18 Pelle van de Bor , John Brennan , John A. Regan , Jonathan Mackey

Elucidating photochemical reactions is vital to understand various biochemical phenomena and develop functional materials such as artificial photosynthesis and organic solar cells, albeit its notorious difficulty by both experiments and…

Chemical Physics · Physics 2022-01-26 Keita Omiya , Yuya O. Nakagawa , Sho Koh , Wataru Mizukami , Qi Gao , Takao Kobayashi

Over many years, computational simulations based on Density Functional Theory (DFT) have been used extensively to study many different materials at the atomic scale. However, its application is restricted by system size, leaving a number of…

Mesoscale and Nanoscale Physics · Physics 2018-12-05 Carlos Romero-Muñiz , Ayako Nakata , Pablo Pou , David R. Bowler , Tsuyoshi Miyazaki , Rubén Pérez

The chemical kinetics ODEs arising from operator-split reactive-flow simulations were solved on GPUs using explicit integration algorithms. Nonstiff chemical kinetics of a hydrogen oxidation mechanism (9 species and 38 irreversible…

Computational Physics · Physics 2013-11-05 Kyle E Niemeyer , Chih-Jen Sung

We have combined our adaptive configuration interaction (ACI) [J.B. Schriber and F.A. Evangelista, J. Chem. Phys. 144, 161106 (2016)] with a density-fitted implementation of the second-order perturbative multireference driven similarity…

Chemical Physics · Physics 2018-08-29 Jeffrey B. Schriber , Kevin P. Hannon , Francesco A. Evangelista

This paper presents a robust and efficient very high-order scheme for compressible flow simulation, addressing critical limitations of existing high-order methods. The proposed scheme combines the compact gas-kinetic scheme (CGKS) with an…

Computational Physics · Physics 2025-09-04 Junlei Mu , Hong Zhang , Xing Ji , Yang Zhang , Gang Chen , Kun Xu

Recent advances in selected CI, including the adaptive sampling configuration interaction (ASCI) algorithm and its heat bath extension, have made the ASCI approach competitive with the most accurate techniques available, and hence an…

We investigate the trade-offs between accuracy and efficiency for several flavors of the dissipative mode-space NEGF algorithm with the self-consistent Born approximation for DFT Hamiltonians. Using these models, we then demonstrate the…

Mesoscale and Nanoscale Physics · Physics 2023-10-16 Aryan Afzalian , Fabian Ducry

Reducing the energy expended to carry out a computational task is important. In this work, we explore the prospects of meeting Quality-of-Service requirements of tasks on a multi-core system while adjusting resources to expend a minimum of…

Hardware Architecture · Computer Science 2019-11-14 Mehrzad Nejat , Madhavan Manivannan , Miquel Pericas , Per Stenstrom

Within scientific and real life problems, classification is a typical case of extremely complex tasks in data-driven scenarios, especially if approached with traditional techniques. Machine Learning supervised and unsupervised paradigms,…

Instrumentation and Methods for Astrophysics · Physics 2018-07-13 Giuseppe Angora , Massimo Brescia , Stefano Cavuoti , Giuseppe Riccio , Maurizio Paolillo , Thomas H. Puzia

We demonstrate how to determine numerically nearly exact orthonormal orbitals that are optimal for evaluation of the energy of arbitrary (correlated) states of atoms and molecules by minimization of the energy Lagrangian. Orbitals are…

With the rapid advances in programmable materials, reconfigurable intelligent surfaces (RIS) have become a pivotal technology for future wireless communications. The simultaneous transmitting and reflecting reconfigurable intelligent…

Machine Learning · Computer Science 2025-12-02 Yujie Huang , Haibin Wan , Xiangcheng Li , Tuanfa Qin , Yun Li , Jun Li , Wen Chen

The Dynamical Graph Grammar (DGG) formalism can describe complex system dynamics with graphs that are mapped into a master equation. An exact stochastic simulation algorithm may be used, but it is slow for large systems. To overcome this…

Quantitative Methods · Quantitative Biology 2024-07-16 Eric Medwedeff , Eric Mjolsness

We have developed and implemented a new quantum molecular dynamics approximation that allows fast and accurate simulations of dense plasmas from cold to hot conditions. The method is based on a carefully designed orbital-free implementation…

Plasma Physics · Physics 2015-06-22 Travis Sjostrom , Jerome Daligault

We present a Gaussian-basis implementation of orbital-free density-functional theory (OF-DFT) in which the trust-region image method (TRIM) is used for optimization. This second-order optimization scheme has been constructed to provide…

Chemical Physics · Physics 2021-09-15 Matthew S. Ryley , Michael Withnall , Tom J. P. Irons , Trygve Helgaker , Andrew M. Teale

This study examines several techniques to improve the efficiency of the linearized multireference driven similarity renormalization group truncated to one- and two-body operators [MR-LDSRG(2)]. We propose a sequential MR-LDSRG(2)…

Chemical Physics · Physics 2019-03-29 Tianyuan Zhang , Chenyang Li , Francesco A. Evangelista

We have applied the momentum space version of the Density Matrix Renormalization Group method ($k$-DMRG) in quantum chemistry in order to study the accuracy of the algorithm in the new context. We have shown numerically that it is possible…

Strongly Correlated Electrons · Physics 2009-02-06 O. Legeza , J. Roder , B. A. Hess

Particle storage rings are a rich application domain for online optimization algorithms. The Cornell Electron Storage Ring (CESR) has hundreds of independently powered magnets, making it a high-dimensional test-problem for algorithmic…

In this contribution, we present the implementation of a second-order CASSCF algorithm in conjunction with the Cholesky decomposition of the two-electron repulsion integrals. The algorithm, called Norm-Extended Optimization, guarantees…

Chemical Physics · Physics 2021-04-09 Tommaso Nottoli , Jürgen Gauss , Filippo Lipparini