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The paper addresses the problem of the self-interaction correction (SIC) in static calculations of atoms and molecules. Key observable is the electron removal energy, the energy required to remove one electron from the given system and to leave it in a definite hole state whereby we discuss hole states not only in the Highest Occupied Molecular Orbital (HOMO), but also deeper lying holes. To that end, we employ a newly developed technique to compute a stationary state for a configuration with a definite hole in a chosen single-particle state. We also compare two different definitions of removal energies, first, the genuine one taking the difference of the total energy of the original system and the energy of final system sustaining the hole, and second, simply the single-particle energy in the original system. According to Koopman’s theorem, both should be close to each other. Four different systems are considered, one atom and three molecules with different bond types, covalent, metallic, and dipolar. The general result is that any SIC brings considerable improvement as compared to the initial Local-Density Approximation (LDA), the better the closer the hole stays to the HOMO. There are variations between different SIC approximations whereby systems with strong binding (atom and covalent molecule) show least variations. Here, the quality of Koopman’s theorem is very satisfying for the HOMO and degrades slightly toward deeper binding. Systems with metallic or dipolar binding are more reactive and show stronger changes with approximation and hole level.

Algebraic collective model (ACM) calculations for the even-even selenium isotopes $^{86,88}\mathrm{Se}$ have been performed to describe collective properties of these two transitional nuclei with only two and four valence neutrons, respectively. From the perspective of the ACM the nuclei turn out to be only weakly deformed, described by a very $\ensuremath{\gamma}$-soft potential. This is confirmed by Skyrme and Gogny energy density functional calculations. Additionally, the fully microscopic symmetry conserving configuration mixing method with the Gogny interaction has been applied to the study of these isotopes. The results show the transitional character of $^{86}\mathrm{Se}$ and the relevant role of the triaxial degree of freedom in the structure of these nuclei.

We report the first use of the effective QMC energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the non-relativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having clear physical basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist however multiple Skyrme paramater sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, as derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter., 9 pages, 1 table, 4 figures; in print in Phys. Rev. Letters. A minor change in the abstract, a few typos corrected and some small technical adjustments made to comply with the journal regulations

We investigate from a theoretical perspective a possible pump and probe scenario for analyzing the rotational motion of free deformed metal clusters considering as test case an ensemble of Na7+ clusters. To that end, we develop a simple classical model for the orientational dynamics and rate equations for the ionizing effect of laser pulses. The model parameters are determined microscopically by time-dependent density functional theory for the cluster electrons and a detailed description of the cluster ions by local pseudo-potentials. We find that pump and probe analysis can very well resolve the rotational motion provided that the laser parameters are properly tuned to the Me surface plasmon of the given sample. Moreover, we see that the laser pulses burn a hole into the distribution of orientations. Stroboscopic repetition of pulses will allow to produce an ensemble clusters oriented in a direction perpendicular to the laser polarization axis.

We discuss the response of the H9+ cluster to an excitation by an intense laser beam. Calculations are done within the framework of TDLDA-MD, an approach which has proven to provide a robust tool for investigations in metal cluster dynamics. We first discuss static and low energy properties of H9+ and make comparisons with other existing ab initio results. We then explore the various excitation/deexcitation scenarios as a function of the laser parameters.

International audience; Photoinduced molecular processes start with the interaction of the instantaneous electric field of the incident light with the electronic degrees of freedom. This early attosecond electronic motion impacts the fate of the photoinduced reactions. We report the first observation of attosecond time scale electron dynamics in a series of small- and medium-sized neutral molecules (N2, CO2, and C2H4), monitoring time-dependent variations of the parent molecular ion yield in the ionization by an attosecond pulse, and thereby probing the time-dependent dipole induced by a moderately strong near-infrared laser field. This approach can be generalized to other molecular species and may be regarded as a first example of molecular attosecond Stark spectroscopy.

Investigations of exotic cluster-like phenomena in the framework of the Skyrme-Hartree-Fock approach are reported. The occurrence of highly excited isomeric states is discussed in connection with the question of their stability in static and time-dependent Hartree Fock (TDHF) calculations. We find rotational stabilization of a 4α chain structure in 16O occurring for a limited range of angular momenta. A toroidal configuration of 40Ca was also stabilized by rotation and provides a very interesting example of rotation about a symmetry axis with a strictly quantized total angular momentum. Finally we look at the formation of nuclear pasta phases in a time-dependent approach and their classification.

The width of the plasmon resonance in the clusters ${\mathrm{Na}}_{9}^{+}$, ${\mathrm{Na}}_{21}^{+}$, and ${\mathrm{Na}}_{41}^{+}$ is investigated in the framework of the structure-averaged jellium model and compared with recent experimental data. The two leading mechanisms for the line broadening are fragmentation of the resonance into nearby 1ph states and splitting through thermal quadrupole fluctuations. The fragmentation becomes activated mainly through octupole fluctuations and it gives the dominating contribution to the width.

We investigate the excitation spectra of closed-shell 3 He droplets using a flexible formulation of the RPA which has been presented in preceeding papers. The calculations are based on an energy functional which thorougly employs finite-range interactions. We compare the results for different stages in a hierarchy of approximations to the full RPA. We furthermore discuss the consequences of taking the zero-range limit of the present energy functional, i.e. of using Skyrme-type interactions

Liquid3He droplets and their shell structure are investigated in the framework of mean-field calculations using a recently developed effective energy functional which employs realistic finite range interactions throughout. The samples range fromN=20 up toN=1360. The shell closures found agree with the harmonic oscillator scheme up toN=168. Above that, magic droplets appear atN=198, 274, 300, 368, 398, 482, 516... The first and second differences of the free energy are computed as signals for the shell structure in future experiments. Shell closures are found to be still visible in these signals at comparatively high temperatures. The finite range character of the effective interaction generates oscillations in the density profile which are suppressed in comparable calculations with zero range interactions.

Outgoing from a time-dependent theory of correlations, we present a stochastic differential equation for the propagation of ensemble of Slater determinants, called stochastic time-dependent Hartree-Fock (stochastic TDHF). These ensembles are allowed large fluctuations to develop in the Hartree-Fock mean fields. An alternative stochastic differential equation, the Boltzmann-Langevin equation, can be derived from stochastic TDHF by averaging over subensembles with small fluctuations.

A new semi-microscopic energy functional for Hartree-Fock calculations in liquid 3He is presented, which employs finite range forces throughout. It contains the polarization potentials and the Skyrme force as limiting cases. The parameters of the functional are uniquely fixed to these limiting cases. In addition to the reproduction of the ground state of liquid 3He and its Landau parameters, a good simultaneous description of zero sound at finite momentum transfer and of the surface tension of semi-infinite 3He is obtained.

We present the first realization of Stochastic TDHF, a theory which goes beyond pure mean-field dynamics, embracing dissipation as well as fluctuations. Applications to heavy-ion collisions in the Fermi energy domain are given and analyzed in terms of dissipative features and Intermediate Mass Fragment production.

The self-consistent separable RPA (random phase approximation) method is formulated for Skyrme forces with pairing. The method is based on a general self-consistent procedure for factorization of the two-body interaction. It is relevant for various density- and current-dependent functionals. The contributions of the time-even and time-odd Skyrme terms as well as of the Coulomb and pairing terms to the residual interaction are taken self-consistently into account. Most of the expression have a transparent analytical form, which makes the method convenient for the treatment and analysis. The separable character of the residual interaction allows to avoid diagonalization of high-rank RPA matrices and thus to minimize the calculation effort. The previous studies have demonstrated high numerical accuracy and efficiency of the method for spherical nuclei. In this contribution, the method is specified for axial nuclei. We provide systematic and detailed presentation of formalism and discuss different aspects of the model.

We concentrate on the two most widely used mean-field models, Skyrme-Hartree-Fock and relativistic mean field. We discuss their performance in view of the extended range of experimental information in terms of a guided tour through selected examples of success, failures and subsequent improvement of the models drawn from comparison with key observables as isotopic shifts, trends of binding energies or single-particle spectra. Particular attention is paid to the extrapolative power with respect to superheavy elements (SHE). It turns out that the most important aspect is here the actual level sequence as implied by the given mean-field models. We will compare the performance of available parametrisations and discuss briefly possible improvements.

Two decades ago, with the introduction of Skyrme forces [2.1], Hartree—Fock calculations became feasible in nuclear physics. Since then, they have been applied to a great variety of phenomena, including deformation properties, superheavy nuclei, vibrations, and heavy-ion collisions [2.2]. Nonetheless, their most straightforward application, the description of the ground state of spherical nuclei, remains a useful tool. It serves as the basis for many further applications in nuclear-structure physics; e.g., for studying refinements and variants of the force [2.3], for understanding electron-scattering data, for describing hyperons in nuclei, or for RPA vibrations of the ground-state. Thus, it is desirable to have a code optimized for speed. Such a code also provides a good example of the fast numerical techniques that are necessary for large scale applications.

We derive Modified RPA-equations for small vibrations around excited states. The temperature dependence of collective excitations is examined. The formalism is applied to the ground state and the first excited state of 90Zr in order to confirm the Brink hypothesis.

The equations of motion along a large amplitude collective path vertical-bar q (t),p (t) > are shown to require, in general, complex parameters q and p. It is shown, however, that real values are sufficient if vertical-bar q,p > is constructed by Hartree-Fock with coordinate and momentum constrain. In addition, the motion along the particular paths suggested by the adiabatic time dependent Hartree-Fock theory and by the local harmonic approach is proved to be stable against small imaginary displacements.

Inelastic contributions to photon scattering off nuclei in the Δ-resonance region are calculated assuming a Δ-dominated elementary photon-nucleon scattering amplitude and neglecting Δ-propagation. The inelastic scattering amplitude can then be expressed in terms of transition form factors. Evaluating these in a simple 1p-1h model for the excited states for 12 C and 208 Pb we find sizeable inelastic contributions to higher spin states, which exceed the elastic cross section by an order of magnitude at higher momentum transfer. The actual size of inelastic contributions depends sensitively on the range of excitation energies taken into account.

The relativistic mean-field model has been succesfully applied in various fields of nuclear physics, heavy ion physics and astrophysics, for reviews see [1,2,3]. The model fascinates by its simplicity. It consists of Dirac-nucleons interacting via mesonic mean-fields and the contributions from the Dirac-sea of antinucleons is usually neglected. Yet, the relativistic mean-field model provides an excellent description of nuclear ground-state properties and several other nuclear features. It can very well compete with similar nonrelativistic models. But it has the additional bonus that the spin-orbit force and other spin properties are well determined within the relativistic model.

With the concept of redundant spaces a reduction scheme is proposed which makes the generator coordinate method with two conjugate parameters tractable. By means of that, a collective Schrodinger equation is derived which proves to be identical to the one obtained by consistent quantisation of the classical adiabatic time-dependent Hartree-Fock Hamiltonian.