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Related papers: Orbital Optimization in the Density Matrix Renorma…

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We report a real-space renormalization group (RSRG) algorithm, which is formulated through Baxter's corner transfer matrix (CTM), for two-dimensional (d = 2) classical lattice models. The new method performs the renormalization group…

Statistical Mechanics · Physics 2008-02-03 Tomotoshi Nishino , Kouichi Okunishi

We implement and apply time-dependent density matrix renormalization group (TD-DMRG) algorithms at zero and finite temperature to compute the linear absorption and fluorescence spectra of molecular aggregates. Our implementation is within a…

Chemical Physics · Physics 2019-07-30 Jiajun Ren , Zhigang Shuai , Garnet Kin-Lic Chan

The study of strongly correlated electron systems remains a fundamental challenge in condensed matter physics, particularly in two-dimensional (2D) systems hosting various exotic phases of matter including quantum spin liquids,…

Strongly Correlated Electrons · Physics 2025-07-01 Hui-Ke Jin , Rong-Yang Sun , Hong-Hao Tu , Yi Zhou

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

Density Matrix Renormalization Group (DMRG) and its extensions in the form of Matrix Product States (MPS) are arguably the choice for the study of one dimensional quantum systems in the last three decades. However, due to the limited…

Strongly Correlated Electrons · Physics 2023-04-13 Xiangjian Qian , Mingpu Qin

A momentum-space approach of the density-matrix renormalization-group (DMRG) method is developed. Ground state energies of the Hubbard model are evaluated using this method and compared with exact diagonalization as well as quantum…

Condensed Matter · Physics 2009-10-28 T. Xiang

We improve the density-matrix renormalization group (DMRG) evaluation of the Kubo formula for the zero-temperature linear conductance of one-dimensional correlated systems.The dynamical DMRG is used to compute the linear response of a…

Strongly Correlated Electrons · Physics 2018-10-08 Jan-Moritz Bischoff , Eric Jeckelmann

We describe the implementation of orbital optimization for the models in the perfect pairing hierarchy [Lehtola et al, J. Chem. Phys. 145, 134110 (2016)]. Orbital optimization, which is generally necessary to obtain reliable results, is…

Strongly Correlated Electrons · Physics 2018-03-08 Susi Lehtola , John Parkhill , Martin Head-Gordon

The Density Matrix Renormalization Group (DMRG) method scales exponentially in the system width for models in two dimensions, but remains one of the most powerful methods for studying 2D systems with a sign problem. Reviewing past…

Strongly Correlated Electrons · Physics 2012-03-15 E. M. Stoudenmire , Steven R. White

Iron-sulfur clusters comprise an important functional motif of the catalytic centers of biological systems, capable of enabling important chemical transformations at ambient conditions. This remarkable capability derives from a notoriously…

A new approach to large-scale nuclear structure calculations, based on the Density Matrix Renormalization Group (DMRG), is described. The method is tested in the context of a problem involving many identical nucleons constrained to move in…

Nuclear Theory · Physics 2011-05-12 J. Dukelsky , S. Pittel

In order to extend the density-matrix renormalization-group (DMRG) method to two-dimensional systems, we formulate two alternative methods to prepare the initial states. We find that the number of states that is needed for accurate energy…

Condensed Matter · Physics 2007-05-23 Shoudan Liang , Hanbin Pang

We review the variational principle in the density matrix renormalization group (DMRG) method, which maximizes an approximate partition function within a restricted degrees of freedom; at zero temperature, DMRG mini- mizes the ground state…

Statistical Mechanics · Physics 2009-10-28 T. Nishino , K. Okunishi

We extend the spin-adapted density matrix renormalization group (DMRG) algorithm of McCulloch and Gulacsi [Europhys. Lett.57, 852 (2002)] to quantum chemical Hamiltonians. This involves two key modifications to the non-spin-adapted DMRG…

Chemical Physics · Physics 2014-08-22 Sandeep Sharma , Garnet Kin-Lic Chan

We investigate convergence of the density matrix renormalization group (DMRG) in the thermodynamic limit for gapless systems. Although the DMRG correlations always decay exponentially in the thermodynamic limit, the correlation length at…

Strongly Correlated Electrons · Physics 2009-10-31 Martin Andersson , Magnus Boman , Stellan Ostlund

We have extended the density matrix renormalization group (DMRG) approach to two-fluid open many-fermion systems governed by complex-symmetric Hamiltonians. The applications are carried out for three- and four-nucleon (proton-neutron)…

Nuclear Theory · Physics 2009-01-22 J. Rotureau , N. Michel , W. Nazarewicz , M. Ploszajczak , J. Dukelsky

The second-order multireference driven similarity renormalization group perturbation theory (DSRG-MRPT2) theory provides an efficient means of correcting the dynamical correlation with the multiconfiguration reference function. The…

Chemical Physics · Physics 2022-02-01 Jae Woo Park

The Density Matrix Renormalization Group (DMRG) algorithm is a powerful tool for solving eigenvalue problems to model quantum systems. DMRG relies on tensor contractions and dense linear algebra to compute properties of condensed matter…

Distributed, Parallel, and Cluster Computing · Computer Science 2021-01-26 Ryan Levy , Edgar Solomonik , Bryan K. Clark

We present a general approach to converge excited state solutions to any quantum chemistry orbital optimization process, without the risk of variational collapse. The resulting Square Gradient Minimization (SGM) approach only requires…

Chemical Physics · Physics 2020-03-11 Diptarka Hait , Martin Head-Gordon

In some cases the state of a quantum system with a large number of subsystems can be approximated efficiently by the density matrix renormalization group, which makes use of redundancies in the description of the state. Here we show that…

Strongly Correlated Electrons · Physics 2009-02-03 Michael J. Hartmann , Javier Prior , Stephen R. Clark , Martin B. Plenio