Coherent-states dynamics: A Tribute to N. Yngve Öhrn

Inspired by Öhrn's electron nuclear dynamics (END), a new coherent-states dynamics (CSD) to study chemical reactions is presented. CSD exploits basic properties of coherent states (CS) sets to represent the electrons and nuclei in a reactive system, and advances the concept of quasi-classical CS to formulate quantum/classical treatments. An original feature in CSD is its systematic employment of different types of CS to address specific chemical problems; some of those CS have been created by this author. In that context, END is revisited and some modifications are suggested. A full CSD procedure to calculate chemical reaction properties (e.g. differential cross sections) is also introduced in conjunction with semiclassical techniques. Res.ults of simulations and properties calculations of the He⁺ C ₂H₄ and H⁺ + CO₂ reactive systems at E_Lab = 30 eV are presented in comparison with experimental data. Current efforts in the CSD project (such as a CSD compute grid implementation and a CSD density-functional-theory formulation) are finally discussed.