An overview of the main achievements of the Laboratory of Quantum Chemistry of the Institute of Chemistry of the Academy of Sciences of Moldova during the 50 year of its existence is briefly outlined. The main fundamental “non-transient” result obtained in this laboratory is the generalization of the Jahn-Teller effect theory formulated and proved as a general law of instability of polyatomic systems and its application to a variety of physical, chemical, and biological problems, including al-range spectroscopy, geometry and spectra of molecular systems, structural phase transitions, ferroelectricity, stereochemistry and crystal chemistry, chemical activation and reactivity, electron transfer in mixed-valence compounds, and electron-conformational transitions in biological systems.