# Implementation of the SU(2) Hamiltonian symmetry for the DMRG algorithm

## Description

Abstract In the Density Matrix Renormalization Group (DMRG) algorithm (White, 1992, 1993) [1,2], Hamiltonian symmetries play an important rôle. Using symmetries, the matrix representation of the Hamiltonian can be blocked. Diagonalizing each matrix block is more efficient than diagonalizing the original matrix. This paper explains how the the DMRG++ code (Alvarez, 2009) [3] has been extended to handle the non-local SU(2) symmetry in a model independent way. Improvements in CPU times compared to runs w... Title of program: DMRG++ Catalogue Id: AEDJ_v2_0 Nature of problem Strongly correlated electrons systems, display a broad range of important phenomena, and their study is a major area of research in condensed matter physics. In this context, model Hamiltonians are used to simulate the relevant interactions of a given compound, and the relevant degrees of freedom. These studies rely on the use of tight-binding lattice models that consider electron localization, where states on one site can be labeled by spin and orbital degrees of freedom. The calculation of pro ... Versions of this program held in the CPC repository in Mendeley Data AEDJ_v1_0; DMRG++; 10.1016/j.cpc.2009.02.016 AEDJ_v2_0; DMRG++; 10.1016/j.cpc.2012.04.025 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)