A review of the methods developed within Theoretical Chemistry to study matter in many spatial and temporal scales is presented. The scientific career of a well known theoretical chemist is used to show how the astonishing advances that have been achieved in four decades in the development of theories, codes (algorithms) and computer technology allow nowadays the reliable study of the electronic structure of systems whose sizes were unmanageable forty years ago. It is emphasized that the central difficulty in studying Chemistry from a theoretical perspective is that, in every scale, one deals with a many-body problem whose solution and comprehension are still an unsolved and fascinating scientific challenge.
Vela, A. (2016). Logros y perspectivas de la Química Teórica. Educacion Quimica, 27(4), 278–285. https://doi.org/10.1016/j.eq.2016.09.001