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Related papers: Adaptive multiconfigurational wave functions

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The task of computing wavefunctions that are accurate, yet simple enough mathematical objects to use for reasoning has long been a challenge in quantum chemistry. The difficulty in drawing physical conclusions from a wavefunction is often…

Chemical Physics · Physics 2024-03-12 Nicole M. Braunscheidel , Arnab Bachhar , Nicholas J. Mayhall

We study three wave function optimization methods based on energy minimization in a variational Monte Carlo framework: the Newton, linear and perturbative methods. In the Newton method, the parameter variations are calculated from the…

Chemical Physics · Physics 2015-06-26 Julien Toulouse , C. J. Umrigar

In this paper we develop two conforming finite element methods for a fourth order bi-wave equation arising as a simplified Ginzburg-Landau-type model for d-wave superconductors in absence of applied magnetic field. Unlike the biharmonic…

Numerical Analysis · Mathematics 2009-02-09 Xiaobing Feng , Michael Neilan

This work considers reconstructing a target signal in a context of distributed sparse sources. We propose an efficient reconstruction algorithm with the aid of other given sources as multiple side information (SI). The proposed algorithm…

Computer Vision and Pattern Recognition · Computer Science 2016-05-24 Huynh Van Luong , Jürgen Seiler , André Kaup , Søren Forchhammer

In this paper we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on shell approach for the scattering matrix, commonly…

High Energy Physics - Phenomenology · Physics 2011-01-28 J. Yamagata-Sekihara , J. Nieves , E. Oset

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

The multi-configurational self-consistent field theory is considered the standard starting point for almost all multireference approaches required for strongly-correlated molecular problems. The limitation of the approach is generally given…

Chemical Physics · Physics 2015-10-14 Robert E. Thomas , Qiming Sun , Ali Alavi , George H. Booth

In this work we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on shell approach for the scattering matrix, commonly…

High Energy Physics - Phenomenology · Physics 2011-01-20 J. Yamagata-Sekihara , J. Nieves , E. Oset

This paper investigates constructive interference (CI)-based waveform design for phase shift keying and quadrature amplitude modulation symbols under relaxed block-level power constraints in multi-user multiple-input single-output (MU-MIMO)…

Signal Processing · Electrical Eng. & Systems 2025-08-07 Xiao Tong , Lei Lei , Ang Li , A. Lee Swindlehurst , Symeon Chatzinotas

In this work, we present a time-dependent (TD) selected configuration interaction method based on our recently-introduced adaptive configuration interaction (ACI). We show that ACI, in either its ground or excited state formalisms, is…

Chemical Physics · Physics 2020-01-08 Jeffrey B. Schriber , Francesco A. Evangelista

This paper proposes a robust reduced-rank scheme for adaptive beamforming based on joint iterative optimization (JIO) of adaptive filters. The scheme provides an efficient way to deal with filters with large number of elements. It consists…

Information Theory · Computer Science 2013-03-18 Lei Wang , Rodrigo C. de Lamare

Multimodal fusion faces two robustness challenges: noisy inputs degrade representation quality, and missing modalities cause prediction failures. We propose DCER, a unified framework addressing both challenges through dual-stage compression…

Machine Learning · Computer Science 2026-02-06 Yiwen Wang , Jiahao Qin

We consider the problem of channel estimation and joint active and passive beamforming for reconfigurable intelligent surface (RIS) assisted millimeter wave (mmWave) multiple-input multiple-output (MIMO) orthogonal frequency division…

Signal Processing · Electrical Eng. & Systems 2022-10-05 Xi Zheng , Jun Fang , Hongwei Wang , Peilan Wang , Hongbin Li

Reconfigurable massive multiple-input multiple-output (RmMIMO), as an electronically-controlled fluid antenna system, offers increased flexibility for future communication systems by exploiting previously untapped degrees of freedom in the…

Information Theory · Computer Science 2024-11-07 Keke Ying , Zhen Gao , Yu Su , Tong Qin , Michail Matthaiou , Robert Schober

The work explores a specific scenario for structural computational optimization based on the following elements: (a) a relaxed optimization setting considering the ersatz (bi-material) approximation, (b) a treatment based on a nonsmoothed…

Computational Engineering, Finance, and Science · Computer Science 2021-08-06 J. Oliver , D. Yago , J. Cante , O. Lloberas-Valls

We propose a method to construct the ground state $\psi(\lambda)$ of local lattice hamiltonians with the generic form $H_0 + \lambda H_1$, where $\lambda$ is a coupling constant and $H_0$ is a hamiltonian with a non degenerate ground state…

Condensed Matter · Physics 2009-10-22 J. G. Esteve , Germán Sierra

In this paper, a novel and robust algorithm is proposed for adaptive beamforming based on the idea of reconstructing the autocorrelation sequence (ACS) of a random process from a set of measured data. This is obtained from the first column…

Information Theory · Computer Science 2021-06-25 Saeed Mohammadzadeh , Vitor H. Nascimento , Rodrigo C. de Lamare , Osman Kukrer

The method used earlier for analysis of correlated nanoscopic systems is extended to infinite (periodic) s-band like systems described by the Hubbard model and its extensions. The optimized single-particle wave functions contained in the…

Strongly Correlated Electrons · Physics 2009-02-18 Jan Kurzyk , Włodzimierz Wójcik , Jozef Spałek

In frequency-division duplex (FDD) massive multiple-input multiple-output (MIMO) systems, the growing number of base station antennas leads to prohibitive feedback overhead for downlink channel state information (CSI). To address this…

Signal Processing · Electrical Eng. & Systems 2024-06-25 Yifan Ma , Hengtao He , Shenghui Song , Jun Zhang , Khaled B. Letaief

Coupled wave equations are popular tool for investigating longitudinal dynamical effects in semiconductor lasers, for example, sensitivity to delayed optical feedback. We study a model that consists of a hyperbolic linear system of partial…

Dynamical Systems · Mathematics 2013-08-12 Jan Sieber