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Related papers: Corresponding Active Orbital Spaces along Chemical…

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We present a novel route to constructing cost-efficient semi-empirical approximations for the non-additive kinetic energy in subsystem density functional theory. The developed methodology is based on the use of Slater determinants composed…

Chemical Physics · Physics 2025-01-13 Larissa Sophie Eitelhuber , Denis G. Artiukhin

Chemical selectivity is a phenomenon displayed by potential energy surfaces (PES) that is relevant for many organic chemical reactions whose PES feature a valley-ridge inflection point (VRI) in the region between two sequential index-1…

Chemical Physics · Physics 2020-07-15 M. Agaoglou , V. J. Garcıa-Garrido , M. Katsanikas , S. Wiggins

The study of isolated defects in solids is a natural target for classical or quantum embedding methods that treat the defect at a high level of theory and the rest of the solid at a lower level of theory. Here, in the context of…

Materials Science · Physics 2023-01-25 Bryan T. G. Lau , Brian Busemeyer , Timothy C. Berkelbach

In the past decade, natural orbital functional (NOF) approximations have emerged as prominent tools for characterizing electron correlation. Despite their effectiveness, these approaches, which rely on natural orbitals and their associated…

Chemical Physics · Physics 2024-04-19 Ion Mitxelena , Mario Piris

Analyzing synthesis pathways for target molecules in a chemical reaction network annotated with information on the kinetics of individual reactions is an area of active study. This work presents a computational methodology for searching for…

Computational Engineering, Finance, and Science · Computer Science 2026-03-31 Adittya Pal , Rolf Fagerberg , Jakob Lykke Andersen , Peter Dittrich , Daniel Merkle

Ab initio calculations face the challenge of describing a complex multiscale quantum many-body system. The nuclear wave function has both strong short-range correlations and long-range contributions. Natural orbitals provide a means of…

Nuclear Theory · Physics 2017-04-11 Chrysovalantis Constantinou

The simulation of intrinsic contributions to molecular properties holds the potential to allow for chemistry to be directly inferred from changes to electronic structures at the atomic level. In the present study, we demonstrate how such…

Chemical Physics · Physics 2023-08-16 Frederik Ø. Kjeldal , Janus J. Eriksen

Evaluating the (dis)similarity of crystalline, disordered and molecular compounds is a critical step in the development of algorithms to navigate automatically the configuration space of complex materials. For instance, a structural…

Materials Science · Physics 2020-02-06 Sandip De , Albert P. Bartók , Gábor Csányi , Michele Ceriotti

Autonomous reaction network exploration algorithms offer a systematic approach to explore mechanisms of complex chemical processes. However, the resulting reaction networks are so vast that an exploration of all potentially accessible…

Chemical Physics · Physics 2024-06-12 Miguel Steiner , Markus Reiher

Active learning methods are rapidly becoming the integral component of automated experiment workflows in imaging, materials synthesis, and computation. The distinctive aspect of many experimental scenarios is the presence of multiple…

Machine Learning · Computer Science 2022-03-22 Maxim Ziatdinov , Yongtao Liu , Sergei V. Kalinin

A general relation is derived for the action difference between two fixed points and a phase space area bounded by the irreducible component of a heteroclinic tangle. The determination of this area can require accurate calculation of…

Chaotic Dynamics · Physics 2015-11-17 Jizhou Li , Steven Tomsovic

Simulation of chemical reactions on quantum computing platforms using quantum classical hybrid algorithms such as the Variational Quantum Eigensolver (VQE) is challenged by the need for a reaction consistent treatment of electron…

Chemical Physics · Physics 2026-03-16 L. Roy , M. Sarkar , M. Tewari , A. Kumar , M. Paranjothy

In this paper, we propose an orbital iteration based parallel approach for electronic structure calculations. This approach is based on our understanding of the single-particle equations of independent particles that move in an effective…

Numerical Analysis · Mathematics 2014-11-06 Xiaoying Dai , Xingao Gong , Aihui Zhou , Jinwei Zhu

Many molecules exhibit multiple rotational isomers (conformers) that interconvert thermally and are difficult to isolate. Consequently, a precise characterization of their role in chemical reactions has proven challenging. We have probed…

We compute highly accurate first principle based \textit{ab initio} adiabatic potential energy surfaces (PESs) using State-Averaged Multi-Configurational Self-Consistent Field (SA-MCSCF) followed by internally contracted Multi-Reference…

Chemical Physics · Physics 2026-03-10 Avik Guchait , Gourhari Jana , Satyam Ravi , Koushik Naskar , Satrajit Adhikari

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

Actinide-containing complexes present formidable challenges for electronic structure methods due to the large number of degenerate or quasi-degenerate electronic states arising from partially occupied 5f and 6d shells. Conventional…

An active space variational calculation of the 2-electron reduced density matrix (2-RDM) is derived and implemented where the active orbitals are correlated within the pair approximation. The pair approximation considers only doubly…

Chemical Physics · Physics 2020-10-13 Kade Head-Marsden , David A. Mazziotti

Knowledge of the repulsive behavior of potential energy curves $V(R)$ at $R\to0$ is necessary for understanding and modeling irradiation processes of practical interest. $V(R)$ is in principle straightforward to obtain from electronic…

Computational Physics · Physics 2020-03-09 Susi Lehtola

We present a new adaptive method for electronic structure calculations based on novel fast algorithms for reduction of multivariate mixtures. In our calculations, spatial orbitals are maintained as Gaussian mixtures whose terms are selected…

Numerical Analysis · Mathematics 2019-06-19 Gregory Beylkin , Lucas Monzon , Xinshuo Yang