One hundred years ago, quantum mechanics began providing a description of phenomena occurring at the atomic and molecular levels, where the laws of classical physics are no longer sufficient. Quantum chemistry aims to understand how atoms and molecules function and to help design new ones.
To celebrate this anniversary, a meeting entitled “1925: From Quantum Numbers to the Periodic Table — A Revolution in Chemistry” was held at the Accademia Nazionale dei Lincei on November 15–16. Although the periodic table of the elements had been envisioned by Mendeleev many years earlier, it was only with Pauli’s exclusion principle in 1925 that it took on a rigorous theoretical foundation capable of explaining why each element occupies a specific position.
This and other key principles of quantum mechanics revolutionized chemistry, allowing us to understand how chemical bonds form and break, to predict the shapes of molecules and the structure of liquids and solids, and to explain their properties. Computational (or quantum) chemistry seeks to solve the complex mathematical equations underlying the behavior of matter, and the conference highlighted the fundamental contribution of this discipline to the study of new drugs, the development of sustainable processes, the design of materials with unusual properties, and the investigation of molecules present in interstellar space.
Today, a century after the birth of quantum mechanics, a new revolution is on the horizon: artificial intelligence, which promises to open up unexplored scenarios in the design of new substances and in the optimization of chemical processes that have a major impact on our lives.