English

Controlling the accuracy of the density matrix renormalization group method: The Dynamical Block State Selection approach

Strongly Correlated Electrons 2009-02-06 v1

Abstract

We have applied the momentum space version of the Density Matrix Renormalization Group method (kk-DMRG) in quantum chemistry in order to study the accuracy of the algorithm in the new context. We have shown numerically that it is possible to determine the desired accuracy of the method in advance of the calculations by dynamically controlling the truncation error and the number of block states using a novel protocol which we dubbed Dynamical Block State Selection (DBSS). The relationship between the real error and truncation error has been studied as a function of the number of orbitals and the fraction of filled orbitals. We have calculated the ground state of the molecules CH2_2, H2_2O, and F2_2 as well as the first excited state of CH2_2. Our largest calculations were carried out with 57 orbitals, the largest number of block states was 1500--2000, and the largest dimensions of the Hilbert space of the superblock configuration was 800.000--1.200.000.

Keywords

Cite

@article{arxiv.cond-mat/0204602,
  title  = {Controlling the accuracy of the density matrix renormalization group method: The Dynamical Block State Selection approach},
  author = {O. Legeza and J. Roder and B. A. Hess},
  journal= {arXiv preprint arXiv:cond-mat/0204602},
  year   = {2009}
}

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12 pages