I. B. Bersuker is a highly accomplished scientist known for his work in quantum chemistry and the Jahn-Teller (JT) and pseudo-JT (PJT) effect theory. His research has covered a wide range of topics, from core polarization in atoms to the prediction of tunneling splitting in JT systems. He has published extensively, with around 425 peer-reviewed publications, including books and major reviews. Bersuker's contributions include the revelation of structural symmetry breaking mechanisms in polyatomic systems, the discovery of novel properties in solids, and the development of theories related to ferroelectricity and multiferroics. Additionally, he has made significant advancements in chemical applications of the JT and PJT effects, with implications for stereochemistry, molecular instabilities, and bioactivity prediction in drug design. Bersuker's distinguished career has been recognized with numerous awards and honors for his scientific achievements.