Impact of theoretical chemistry on chemical and biological sciences

The Nobel Prize in Chemistry, 2013 has been awarded to Martin Karplus, Michael Levitt and Arieh Warshel for their studies on development of multi-scale models for complex chemical systems. This article introduces the readers to the theoreticalmethods developed for the study of complex chemical and biological systems and connects the works of the awardees to this vast area of research. The development of quantum chemistry (QC or QM) to study molecules at electronic level is briefly mentioned. The growth of methods based on classical physics to study large systems at the molecular level (MM) is discussed. The origin of hybridQM/MM techniques to perform multi-scale modelling is then presented. Further, the parallel development of molecular simulations, which connects the macroscopic and the microscopic world elucidating the dynamical properties of molecules, is introduced. Finally, the impact of theoretical chemistry on the advancement of our understanding of complex chemical and biological systems is highlighted.