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We study the dependence of participant-spectator matter, collision rate and density reached on the structural effects using different parameterizations of radius within the framework of Isospin-dependent Quantum Molecular Dynamical Model (IQMD) for the reaction of 40Ar+27Al and 197Au+197Au at three different incident energies i.e. 50, 100 and 400 MeV/nucleon. Our results show a weak dependence of these quantities on the structural effect like the radii of the colliding nuclei at all incident energies for the heavier system compared to the lighter systems.

This paper is a brief review of a time‐dependent, direct, nonadiabatic theory of molecular processes called Electron Nuclear Dynamics (END). This approach to the study of molecular reaction dynamics is a hierarchical theory that can be applied at various levels of approximation. The simplest level of END uses classical nuclei and represents all electrons by a single, complex, determinantal wave function. The wave function parameters such as average nuclear positions and momenta, and molecular orbital coefcients carry the time dependence and serve as dynamical variables. Examples of application are given of the simplest level of END to ion‐atom and ion‐molecule reactions.

This ICCMSE Symposium honors the many accomplishments of Prof. Nils Yngve Ohrn on the occasion of his retirement from the University of Florida. Over the years, Yngve's work has always been focused on the theoretical explanation of experimental phenomena, especially on response and dynamics‐related properties, and he has developed various methods in this pursuit. His work in the 1960's on the electron propagator is very well known, and was the basis of a book that has now appeared in two editions. Later he worked on the Antisymmetrized Geminal Product (AGP) wavefunction (1970's and 1980's), and most recently he has been involved with the development of the Electron Nuclear Dynamics (END) scheme which treats a projectile/target complex as a fully coupled quantum mechanical system of electrons and nuclei. Although Yngve is retiring, he does not intend to stop working, so we expect to have him with us for many years.

Emphasis is directed in this paper towards the accomplishments by Yngve Ohrn in theory of molecular reactions with his Electron Nuclear Dynamics time‐dependent formulation and its competent implementation to a manageable and versatile tool.

K nuclear bound states were generated dynamically within a relativistic mean field (RMF) model. Substantial polarization of the core nucleus was found for light nuclei. The behavior of the dynamically calculated width ΓK as function of the K binding energy was studied. A lower limit of ΓK ∼ 35 – 45 MeV for 1s K nuclear states in light nuclei such as 12C was placed on the width expected for deep binding in the range B K ∼ 100 – 200 MeV.

Theoretical studies of several prospective 2p emitters are performed in a three‐body core+p+p model. Lifetime dependencies on the decay energy are calculated for 19Mg, 30Ar, 34Ca, 45Fe, 48Ni, 54Zn, 62Se and compared to the quasiclassical estimates. An observation of products from the in‐flight decay of 2p emitting nuclei is discussed as an important technique supplementing a standard implantation method for a broad range of lifetimes of prospective 2p emitters. The sensitivity of the model to various aspects of nuclear dynamics is demonstrated on the 45Fe example. Momentum correlations for emitted protons are discussed with the emphasis on 19Mg and 45Fe.

When a molecule is core-excited to a dissociative state, dissociation may occur on the time scale of the core hole decay, i.e. a few femtoseconds. This is discussed in terms of the nuclear dynamics of the dissociation, and the electronic dynamics of the core hole decay. Examples demonstrating different aspects of these phenomena are presented. Semi-classical methods, which provide quantitative information about the dissociation dynamics, are outlined. More advanced theories, including time-dependent quantum mechanics and interference, as well as possible experimental developments, are briefly discussed.

The emission of intermediate‐mass fragments (IMFs) from highly excited nuclei is examined as a function of projectile energy. Near threshold the principal IMF sources are (1) the statistical decay of equilibrated composite systems formed in central collisions and (2) peripheral processes which form projectile‐like ejectiles. In the vicinity of the Fermi energy, nonequilibrium IMF emission, presumably from intermediate impact‐parameter collisions, becomes a third important mechanism. At total bombarding energies in excess of 1 GeV, multifragment emission is also observed. In this report we investigate the evolution of these mechanisms as a function of beam energy in both inclusive and exclusive studies of 14N‐induced reactions below E/A=100 MeV and 3He‐induced reactions up to E/A=1.2 GeV.