Electron Localization-Delocalization Matrices (LDMs)

Abstract

An electron localization-delocalization matrix, or LDM, is a matrix representative of the complete molecular graph. The complete graph, in contrast with the generally-incomplete chemical structure graph, is composed of a link (an edge) between every pair of atoms in the molecule (every pair of vertices). The edges here are not bonds nor bond paths but rather delocalization pathways between every atom pair. The matrix encapsulates information on the electronic distribution in the molecule at an atomic and atomic-pair resolution. It is hence a convenient bridge between quantum chemistry that delivers detailed electronic structure information and bench chemistry that uses the same level of description at which atoms and groups of atoms are exchanged in chemical reactions.