## Abstract In the QM/MM method we have developed (LSCF/MM), the QM and the MM parts are held together by means of strictly localized bonding orbitals (SLBOs). Generally these SLBOs are derived from localized bond orbitals (LBOs) that undergo tails deletion, resulting in a nonpredictable change of
On the importance of orbital localization in QC-DMRG calculations
✍ Scribed by Alexander O. Mitrushchenkov; Guido Fano; Roberto Linguerri; Paolo Palmieri
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 224 KB
- Volume
- 112
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
We investigate the importance of orbital localization in the application of the Density Matrix Renormalization Group (DMRG) technique to ab initio studies of molecular electronic structure. Our previous implementation of DMRG has been generalized to allow for the use of localized nonorthogonal orbitals. Simple cycles of equidistant hydrogen atoms, which are good examples of one dimensional metal‐like lattices with fully delocalized electronic structures, have been taken as test models. In this study, the efficiency of the DMRG method and the importance of orbital localization for the generation of the DMRG building blocks are confirmed. However, it is found that the convergence of the procedure based on nonorthogonal orbitals is slower and requires more DMRG components than the standard orthogonal formulation. Symmetrically orthonormalized atomic orbitals are shown to be a good compromise solution: they satisfy the requirement of orbital localization for the generation of the DMRG blocks and improve the convergence, reducing the number of components of the DMRG expansion. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
📜 SIMILAR VOLUMES
## Abstract Single‐exponential Slater type orbitals of the form ψ~1~ = (1 + __L__~1~(__r__, θ) + __L__~2~(__r__, θ) +…︁+ __L__~__n__~(__r__, θ)) exp (− α__r__) are examined for their potential use as one‐center molecular orbitals. These are then to be used as molecular fragments in a LCMO study. Th