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Magnetic semiconductor materials have potential applications in the field of spintronic devices. In this paper, some nano-device structures based on the magnetic semiconductor NiBr2 monolayer (NiBr2-ML) are designed, their spin-resolved transport and photoelectric properties are studied by using density functional theory combined with non-equilibrium Green's function method. The results show that, both the NiBr2-ML pn-junction diodes and sub-3 nanometer pin-junction field-effect transistors (FETs) exhibit the significant rectification and spin filtering effects in either the armchair or the zigzag direction. The gates can obviously tune the electron transmission of the pin-junction FETs. The current is significantly suppressed with the increase of gate voltages. In addition, NiBr2-ML has a strong response to the blue and green light, thus its phototransistor can generate a strong photocurrent under the irradiation of blue and green light. The research results in this paper reveal the multifunctional characteristics of NiBr2-ML, which provides an important reference for the application of nickel-based dihalides in the field of semiconductor spintronic devices and optoelectronic devices.

The structural optimization for the ground state (X1Σ+) of SiO molecule has been calculated using density functional theory B3P86 method with the basis sets STO-3G, D95**, 6-311G, 6-311++G, 6-311++G** and cc-PVTZ. The conclusion is draun by comparison that the basis set cc-PVTZ is the most suitable for the structural optimization calculation of the ground state (X1Σ+) of SiO molecule. The analytical potential energy curve for the ground state (X1Σ+) of SiO molecule is scanned using B3P86/cc-PVTZ method, and then fitted to the Murrell-Sorbie function using least squares. At last the spectroscopy constants (Be，αe，ωe and ωeχe) related to the analytical potential energy function are calculated and compared with the experimental data.

Sulfur in hydrogen combustion reaction chemistry, which plays an important role in meteorology, combustion reactions, and atmospheric pollution, has been extensively investigated recently. And its reverse reaction has also been a research object gradually. The research in this paper is based on the exact potential energy surface (L S J, Zhang P Y, Han K L, He G Z 2012 J. Chem. Phys. 136 094308), with using the method of quasi-classical trajectory on the exchange reaction of H (D)+SH/SD dynamic properties. In this paper, the scalar properties are calculated, including the cross section, rate constant, opacity function, product vibrational, rotational distributions, product scattering direction, rotational angular momentum orientation, and alignment properties. In this paper, how the collision energy and the isotope affect the reaction H (D)+SH/SD kinetic properties is analyzed in detail. The results show that as collision energy increases, the reaction cross section increases, product backscatter weakens gradually while the product rotational angular momentum alignment and orientation nature strengthen gradually. In addition, the isotope effect has a significant influence on the reaction kinetics. The reaction mechanism which is shown in the title and based on the reaction kinetics and the potential energy surface, is also discussed in this paper.