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Related papers: Orbital Optimization in the Active Space Decomposi…

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We propose a numerical pipeline for shape optimization in naval engineering involving two different non-intrusive reduced order method (ROM) techniques. Such methods are proper orthogonal decomposition with interpolation (PODI) and dynamic…

Numerical Analysis · Mathematics 2019-05-15 Marco Tezzele , Nicola Demo , Gianluigi Rozza

This paper puts forth two new closure models for the proper orthogonal decomposition reduced-order modeling of structurally dominated turbulent flows: the dynamic subgrid-scale model and the variational multiscale model. These models, which…

Computational Physics · Physics 2015-05-28 Zhu Wang , Imran Akhtar , Jeff Borggaard , Traian Iliescu

This paper reports a development in the proper symplectic decomposition (PSD) for model reduction of forced Hamiltonian systems. As an analogy to the proper orthogonal decomposition (POD), PSD is designed to build a symplectic subspace to…

Numerical Analysis · Mathematics 2016-03-14 Liqian Peng , Kamran Mohseni

The time-dependent restricted-active-space self-consistent-field (TD-RASSCF) method is formulated based on the TD variational principle. In analogy with the configuration-interaction singles (CIS), singles-and-doubles (CISD),…

Quantum Physics · Physics 2014-06-26 Haruhide Miyagi , Lars Bojer Madsen

Band structure unfolding is a key technique for analyzing and simplifying the electronic band structure of large, internally distorted supercells that break the primitive cell's translational symmetry. In this work, we present an efficient…

Materials Science · Physics 2026-02-10 Jingkai Quan , Nikita Rybin , Matthias Scheffler , Christian Carbogno

Natural orbital functional (NOF) theory offers a promising approach for studying strongly correlated systems at an affordable computational cost, with an accuracy comparable to highly demanding wavefunction-based methods. However, its…

Strongly Correlated Electrons · Physics 2025-01-31 Juan Felipe Huan Lew-Yee , Jorge M. del Campo , Mario Piris

We propose a new method to characterize the spatial distribution of particles' vibrations in solids with much lower computational costs compared to the usual normal mode analysis. We excite the specific vibrational mode in a two dimensional…

Soft Condensed Matter · Physics 2016-05-24 Elsen Tjhung , Takeshi Kawasaki

We present our theoretical results on the mechanism of two transitions in vanadium spinel oxides $A$V$_2$O$_4$ ($A$=Zn, Mg, or Cd) in which magnetic V cations constitute a geometrically-frustrated pyrochlore structure. We have derived an…

Strongly Correlated Electrons · Physics 2007-05-23 Yukitoshi Motome , Hirokazu Tsunetsugu

Reduced-density-matrix-functional theory is applied to open-shell systems. We introduce a spin-restricted formulation by appropriately expressing approximate correlation-energy functionals in terms of spin-dependent occupation numbers and…

Strongly Correlated Electrons · Physics 2007-05-23 N. N. Lathiotakis , N. Helbig , E. K. U. Gross

In this contribution we investigate in mathematical modeling and efficient simulation of biological cells with a particular emphasis on effective modeling of structural properties that originate from active forces generated from…

Numerical Analysis · Mathematics 2021-11-02 Tobias Leibner , Maja Matis , Mario Ohlberger , Stephan Rave

We introduce a robust optimization method for flip-free distortion energies used, for example, in parametrization, deformation, and volume correspondence. This method can minimize a variety of distortion energies, such as the symmetric…

Graphics · Computer Science 2022-11-17 Oded Stein , Jiajin Li , Justin Solomon

We demonstrate that variations in molecular chemisorption energy on different metals, different surface terminations, and different strain conditions can be accounted for by orbital-specific changes in the substrate electronic structure.…

Materials Science · Physics 2007-05-23 Sara E. Mason , Ilya Grinberg , Andrew M. Rappe

Simulating the dynamics of charged particles in quasi-two-dimensional (quasi-2D) nanoconfined systems presents a significant computational challenge due to the long-range nature of electrostatic interactions and the geometric anisotropy. To…

Soft Condensed Matter · Physics 2026-01-07 Zecheng Gan , Xuanzhao Gao , Yuqing Li

We demonstrate that accurate computation of the spectral proper orthogonal decomposition (SPOD) critically depends on the choice of frequency resolution. Using both artificially generated data and large-eddy simulation data of a turbulent…

Fluid Dynamics · Physics 2024-02-27 Liam Heidt , Tim Colonius

Multi-configurational wave functions are known to describe electronic structure across a Born-Oppenheimer surface qualitatively correct. However, for quantitative reaction energies, dynamical correlation originating from the many…

Chemical Physics · Physics 2020-04-16 Christopher J. Stein , Markus Reiher

We present OBDF-SQD, a hybrid quantum-classical method that combines one-body downfolding~(OBDF) based on one-body M\o{}ller--Plesset second-order perturbation theory (OBMP2) with sample-based quantum diagonalization~(SQD) for use in…

Quantum Physics · Physics 2026-05-12 Thien Ngoc Tran , Lan Nguyen Tran

Thermally Activated Delayed Fluorescence (TADF) emitters must satisfy two competing requirements: small singlet-triplet energy gaps for thermal upconversion and sufficient spin-orbit coupling for fast reverse intersystem crossing.…

Diverse optimization algorithms correctly identify, in finite time, intrinsic constraints that must be active at optimality. Analogous behavior extends beyond optimization to systems involving partly smooth operators, and in particular to…

Optimization and Control · Mathematics 2019-02-05 Adrian S. Lewis , Calvin Wylie

In the present article, we show how to formulate the partially contracted n-electron valence second order perturbation theory (NEVPT2) energies in the atomic and active molecular orbital basis by employing the Laplace transformation of…

Chemical Physics · Physics 2017-06-28 Benjamin Helmich-Paris , Stefan Knecht

Reduced-order simulation is an emerging method for accelerating physical simulations with high DOFs, and recently developed neural-network-based methods with nonlinear subspaces have been proven effective in diverse applications as more…

Machine Learning · Computer Science 2024-09-09 Aoran Lyu , Shixian Zhao , Chuhua Xian , Zhihao Cen , Hongmin Cai , Guoxin Fang