The cross-section calculation systematics for nuclear reactions have great importance in describing the particle-induced excitation of nuclei. In this study, for 14-15 MeV of incident neutron energy, it has been suggested new empirical formulae to describe the (n, 2p) reactions cross sections. The new empirical formulae have been obtained for 29≤A≤159, 29≤A≤103 and 133≤A≤159 mass ranges which are dependent on s=(N-Z)/A asymmetry parameter. The asymmetry parameters have been obtained by modifying the original Levkovski formula. Then, EXFOR data has been studied by applying the least square fitting method and (n, 2p) reactions systematics has been revealed. The statistical dependence (R2) of these data was examined in the 29≤A≤159 total mass range. The calculated results from the obtained formulae have been compared with the literature data. The predictions of our formulae are in good agreement with the EXFOR data for 29≤A≤159 and 29≤A≤103 mass range.

Asymmetry parameters of the electric field gradient tensor at (75) As nuclei were determined for chalcogenide glassy semiconductors (CGS) of the Ge-As-Se system by comparing the experimental and simulated (75) As nuclear quadrupole resonance nutation interferograms. The electric field gradient asymmetry in CGS was analyzed, and it is believed that a structural change in these glassy semiconductors takes place at r¯ =  2.425. Electron paramagnetic resonance spectra of the Ge-As-Se system were obtained for the first time. A comparison was made between the results of analysis of the Ge-As-Se system by nuclear quadrupole resonance and electron paramagnetic resonance methods, and this allowed us to make the supposition that a structural phase transition occurs at r¯ = 2.4 from two-dimensional to three-dimensional CGS structure.