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Related papers: Targeted Excited State Algorithms

200 papers

We present a first principles strategy for developing state-specific density functional approximations for excited states. We first clarify why approaches based on conventional ground state approximations miss density-driven correlations,…

Chemical Physics · Physics 2025-06-09 Tim Gould , Stephen G Dale , Leeor Kronik , Stefano Pittalis

We show that from the point of view of the generalized pairing Hamiltonian, the atomic nucleus is a system with small entanglement and can thus be described efficiently using a 1D tensor network (matrix-product state) despite the presence…

Nuclear Theory · Physics 2024-03-07 Roman Rausch , Cassian Plorin , Matthias Peschke , Christoph Karrasch

Early work extending the Kohn-Sham theory to excited states utilized an ensemble average of the Hamiltonian considered as a functional of the corresponding average density. We propose and develop an alternative that utilizes the matrix…

Atomic Physics · Physics 2007-05-23 Abraham Klein , Reiner M. Dreizler

We extend the density matrix renormalization group method to exploit Parity, $C_2$ (rotation by $\pi$) and electron-hole symmtries of model Hamiltonians. We demonstrate the power of this method by obtaining the lowest energy states in all…

Condensed Matter · Physics 2007-05-23 S. Ramasesha , Swapan K. Pati , H. R. Krishnamurthy , Z. Shuai , J. L. Bredas

Theoretical understanding of strongly correlated systems in one spatial dimension (1D) has been greatly advanced by the density-matrix renormalization group (DMRG) algorithm, which is a variational approach using a class of…

Statistical Mechanics · Physics 2013-07-18 M. L. Wall , Lincoln D. Carr

Excited state properties play a pivotal role in various chemical and physical phenomena, such as charge separation and light emission. However, the primary focus of most existing quantum algorithms has been the ground state, as seen in…

The density-matrix renormalization group method (DMRG) has established itself over the last decade as the leading method for the simulation of the statics and dynamics of one-dimensional strongly correlated quantum lattice systems. In the…

Strongly Correlated Electrons · Physics 2011-01-04 Ulrich Schollwoeck

The prediction of electronic structure for strongly correlated molecules represents a promising application for near-term quantum computers. Significant attention has been paid to ground state wavefunctions, but excited states of molecules…

Quantum Physics · Physics 2025-01-08 Harper R. Grimsley , Francesco A. Evangelista

Problems in quantum chemical simulations, especially achieving accurate excited-state potential energy surfaces, are among the primary applications to achieve quantum utility. On near-term quantum hardware, variants of the variational…

I present a density-matrix renormalization-group (DMRG) method for calculating dynamical properties and excited states in low-dimensional lattice quantum many-body systems. The method is based on an exact variational principle for dynamical…

Strongly Correlated Electrons · Physics 2009-11-07 Eric Jeckelmann

We present a method for finding individual excited states' energy stationary points in complete active space self-consistent field theory that is compatible with standard optimization methods and highly effective at overcoming difficulties…

Strongly Correlated Electrons · Physics 2019-04-12 Lan Nguyen Tran , Jacqueline A. R. Shea , Eric Neuscamman

In this work, we revisited the idea of using the coupled-cluster ground state formalism to target excited states. Our main focus was targeting doubly excited states and double core hole states. Typical equation-of-motion (EOM) approaches…

Chemical Physics · Physics 2019-12-04 Joonho Lee , David W. Small , Martin Head-Gordon

An efficient density matrix renormalization group (DMRG) algorithm is presented and applied to Y-junctions, systems with three arms of $n$ sites that meet at a central site. The accuracy is comparable to DMRG of chains. As in chains, new…

Strongly Correlated Electrons · Physics 2016-03-23 Manoranjan Kumar , Aslam Parvej , Simil Thomas , S. Ramasesha , Z. G. Soos

The density matrix renormalization group (DMRG) is a numerical method that optimizes a variational state expressed by a tensor product. We show that the ground state is not fully optimized as far as we use the standard finite system…

Statistical Mechanics · Physics 2010-05-20 H. Takasaki , T. Hikihara , T. Nishino

We study distributed optimization algorithms for minimizing the average of \emph{heterogeneous} functions distributed across several machines with a focus on communication efficiency. In such settings, naively using the classical stochastic…

Machine Learning · Computer Science 2020-11-18 Ilqar Ramazanli , Han Nguyen , Hai Pham , Sashank J. Reddi , Barnabas Poczos

A simplified version of White's Density Matrix Renormalization Group (DMRG) algorithm has been used to find the ground state of the free particle on a tight-binding lattice. We generalize this algorithm to treat the tight-binding particle…

Strongly Correlated Electrons · Physics 2009-10-31 M. A. Martin-Delgado , G. Sierra , R. M. Noack

The density matrix renormalization group (DMRG) method generates the low-energy states of linear systems of $N$ sites with a few degrees of freedom at each site by starting with a small system and adding sites step by step while keeping…

Strongly Correlated Electrons · Physics 2016-10-05 Manoranjan Kumar , Dayasindhu Dey , Aslam Parvej , S. Ramasesha , Zoltán G. Soos

A novel, exact, theoretical method for the study of the excited states of a system is presented. It is demonstrated how to transform the excited state problem of one Hamiltonian into the ground state problem of an auxiliary one. From this,…

Quantum Physics · Physics 2012-06-22 Ramón Alain Miranda Quintana

We present a variational Monte Carlo algorithm for estimating the lowest excited states of a quantum system which is a natural generalization of the estimation of ground states. The method has no free parameters and requires no explicit…

Computational Physics · Physics 2024-09-04 David Pfau , Simon Axelrod , Halvard Sutterud , Ingrid von Glehn , James S. Spencer

The mean-field solutions of electronic excited states are much less accessible than ground state (e.g.\ Hartree-Fock) solutions. Energy-based optimization methods for excited states, like $\Delta$-scf, tend to fall into the lowest solution…

Chemical Physics · Physics 2022-10-11 Hong-Zhou Ye , Matthew Wellborn , Nathan D. Ricke , Troy Van Voorhis