Orbital ordering in Density Matrix Renormalization Group methods

Claire Ralph, Cornell University

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The Density Matrix Renormalization Group (DMRG) method has shown to be a powerful method as applied to quantum chemistry, but still many questions remain unanswered when one considers applications to molecules. DMRG was developed to treat one-dimensional systems with primarily local interactions; however, a problem arises of how to represent and map a higher-dimensional system to the 1D lattice structure inherent to the current algorithm. We study the use of the Natural Bonding Orbitals and the Lewis structure that arises from these orbitals to propose a simple, chemically intuitive method for defining this mapping. We compare our ordering of orbitals to those previously proposed, such as bandwidth minimization of the one-electron integral matrix.

Abstract Author(s): Claire C. Ralph, Garnet K.L. Chan