Role of the Binding Motifs in the Energy Level Alignment and Conductance of Amine-Gold Linked Molecular Junctions within DFT and DFT + Σ

We investigate, using density functional theory (DFT), the electronic and conducting properties of benzenediamine connected to gold electrodes via different tip structures. We examine a series of binding motifs to the electrodes and calculate the junction spectral properties. We consider corrections to the position of molecular resonances at the junction and discuss different approaches to the calculation of these shifts. We relate the magnitude of these corrections to resonance energies to the atomistic structure of the tip. Benzenediamine DFT-based transmission spectra can be well approximated by a Lorentzian model involving only the highest occupied molecular orbital (HOMO). We show how benzenediamine calculated conductance values in quantitative agreement with previous experiments can be achieved from the combination of DFT-based spectra and corrections to the DFT-based HOMO energy and an accessible Lorentzian model.

Comparison of practical expressions for E1 photon strength functions

The closed-form expressions for the photon strength functions (PSF) are tested using the gamma-decay data of OSLO group. The theoretical calculations are performed for the Lorentzian models of PSF for electric and magnetic dipole gamma-rays. The criteria of minimum of least-square value as well as the root-mean-square deviation factor are used. It is shown that a rather good agreement is obtained within the Simple Modified Lorentzian model for E1 PSF modelling.

THE SIMPLIFIED DESCRIPTION OF DIPOLE RADIATIVE STRENGTH FUNCTION

The gamma-decay strength function is calculated and compared with experimental data to test simple methods of the descriptions of the dipole radiative strength function (RSF) of gamma-decay in the middle-weight and heavy atomic nuclei. Simplified version of the modified Lorentzian model is proposed. It is shown that the phenomenological closed-form models with asymmetric shape can be used for overall estimates of the dipole RSF in the gamma-ray energy region up to about 20 MeV when giant dipole resonance (GDR) parameters are known or the GDR systematics can be adopted.