Is my chemical universe localized or delocalized? is there a future for chemical concepts?

Abstract

The essay discusses the interplay between the two major concepts of molecular description: the localized and delocalized representations. It is shown by means of examples that crossing through the looking glass between the two conceptual worlds intensifies the insight. The role of concepts as generators of our worlds is stressed and it is argued that concepts are needed more than ever in to-day’s computational quantum chemistry.