Searching for a Global alpha-nucleus Potential for Astrophysical Applications

This contribution reports on a systematic investigation of in-beam cross-section measurements of (α,γ) reactions, carried out using a 4π calorimeter. The results are compared to the predictions of the Hauser-Feshbach (HF) theory. This com­ parison puts some constraints on the relevant nuclear properties entering the HF calculations.

Density functional theory (DFT) and Hartree–Fock (HF) calculations of potential p–vinylbenzyl chloride-based macroinitiator for atom transfer radical polymerization

The spectroscopic properties of poly (styrene–co–p–vinylbenzyl chloride) (poly (St-co-VBC)) were investigated by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopic techniques. The molecular geometry and vibrational frequencies of macroinitiator, poly (St-co-VBC), were calculated by using density functional theory (DFT) and Hartree–Fock (HF) methods with 6–31 G+ (d, p) as a basis set. Calculated theoretical values are shown to be in good agreement with that of experimental values. An excellent harmony between the two data sets was verified. Besides, the experimental data of macroinitiator were compared with experimental data of its corresponding monomers such as St and VBC. The dimer and trimer forms of macroinitiator are used as significant contributions for getting an accurate interpretation of the experimental frequencies of poly (St-co-VBC). The results revealed that the change from St and VBC to poly (St-co-VBC) should be characterized by the disappearance of the CH2=CH bonds of the vinyl group and the appearance of the aliphatic C–H and CH2 bonds. The geometrical parameters, Mulliken atomic charges and frontier molecular orbitals energies were also calculated using the same theoretical methods. The chemical shifts were calculated by using the gauge–including atomic orbital method and all the theoretically predicted values were shown to be in good agreement with experimental values. Molecular orbital properties, molecular electrostatic potential, and the potential energy surface for the atom transfer radical polymerization (ATRP) of the macroinitiator were studied with DFT and HF calculations. The potential energy surface of the ATRP initiator is decided by their electronic effect and steric hindrance effect simultaneously.

Systematics of nucleon density distributions and neutron skin of nuclei

Proton and neutron density profiles of 760 nuclei in the mass region of [Formula: see text] are analyzed using the Skyrme energy density for the parameter set SLy4. Simple formulae are obtained to fit the resulting radii and diffuseness data. These formulae are useful to estimate the values of the unmeasured radii and especially in extrapolating charge radii values for nuclei which are far from the valley of stability. Also, it provides an easy way to formulate the density profile for nuclear applications and to perform analytic calculations for bound and/or scattering problems. The obtained neutron and proton root-mean-square (rms) radii and the neutron skin thicknesses are in agreement with the available experimental data and previous Hartree–Fock (HF) calculations.