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Metal chalcogenides have become popular materials for next-generation electronic devices due to their wide band gap and excellent transport properties. Specifically, two-dimensional metal chalcogenides also have outstanding physical properties. For electronic devices, the carrier mobility is a key parameter because it affects the material conductivity and the response time. As a member of metal chalcogenides, GaS has attracted the attention of scholars. In this work, by using first principles calculations and the Wannier function interpolation, the electronic and phonon properties, the electron-phonon interaction, the scattering rate, and the carrier mobility of monolayer and bulk GaS are systematically studied. The results show that GaS is a semiconductor and both monolayer and bulk GaS are dynamically stable. The LO phonon modes at long wavelengths strongly affect the carrier migration in GaS. We give the carrier mobility of monolayer and bulk GaS as a function of temperature (100K500). In addition, we compare the carrier mobility of GaS with several other metal chalcogenides (monolayer and bulk InSe, monolayer GeS, and monolayer GeSe) at 300 K. The results show that an increase in temperature leads to a decrease in the carrier mobility and the electron (hole) mobility of monolayer and bulk GaS is 10.85 cm

Li4SiO4 crystal is a candidate material for tritium breeder material. Vacancy defects and He atoms will be produced in the crystal after neutron irradiation in fusion reactor. In previous research, we learned vacancy defects mainly include VO0, VO2+, and VLi0, meanwhile, He atoms are easy to migrate and aggregate in the crystal. In order to understand the relationship between vacancy defects and He atoms, we use density functional theory (DFT) to study the interaction mechanism between vacancy and He atom. The results show that the local stable sites of He atoms are related to the surrounding charge distribution. VO2+ and VLi0 can capture interstitial He atoms, and it is difficult to escape the vacancies, thereby increasing the nucleation center of He atoms. VO0 promotes the diffusion of He atoms in the interstitial space, which will cause small helium bubbles to merge more easily.

The electronic structure and spectroscopic properties of GeCl

The feasibility of laser cooling of AuF molecule and its cation are investigated from vibrational and rotational perspectives. The spectroscopy of AuF molecule and AuF

Eleven Λ-S states and five Ω states of AsI molecule are calculated at the method of multireference configuration interaction plus Davidson correction (MRCI + Q), and the equilibrium bond length (Re), electron transition energy (Te), harmonic vibrational frequency (ωe), non-harmonic vibrational frequency (ωeΧe) and rotational constant (Be) of these states are fitted. The permanent dipole moments of eleven Λ-S states are also calculated in this paper. On account of the accurate potential energy curves and the transition dipole moment, the Franck-Condon factors and radiative lifetime of the b 1 Σ 0 + + ↔ X 3 Σ 0 + - transition for AsI molecule are calculated. Although it has highly diagonalized Franck-Condon factors, its radiative lifetime is only ms level. The feasibility of laser cooling of AsI molecules is analyzed by comparing it with the monohalide of Group-IIIA.

In this study, the effect of doped metal atoms Pd, Mg and Ti on the release of tritium on the Li2O (111) surface is studied by using density functional theory. On the clean Li2O (111) surface, the formation energies of T2O and T2 are 3.41 eV and 6.30 eV, respectively. About the Li2O (111) surface doped with Pd, Mg and Ti, the T2O molecule are formed spontaneously, and the desorption energies are 1.26, 0.58 and 0.18 eV, respectively. The formation energy of T2 molecule is 2.83 eV, on the surface of Ti-doped Li2O (111). By analyzing Bader charge, charge density difference (CDD), local density of state (LDOS) and the formation energy of oxygen vacancy, we found that dopants can affect the interaction of surrounding atoms through charge transfer and reduce the O vacancy formation energy, and then generate the desorption sites with low activation energy, thereby promoting the formation and desorption of T2O or T2. In a word, doping Pd, Mg and Ti on the Li2O (111) surface can catalyze the release of tritium.

Thirteen Λ-S states of TlBr molecule are calculated by the method of multireference configuration interaction (MRCI) plus Davidson correction (+Q), and the spectroscopic constants of these states are fitted. The dipole moment of thirteen Λ-S states are also included and analyzed in this calculation. Two bound states split into five Ω states with the SOC effect. The interaction between the molecular configurations of TlBr is analyzed with spin orbit coupling. Considering the forbidden transition, transition dipole moment with SOC effect is considered. On account of the accurate potential energy curves and the transition dipole moment, the Franck-Condon factors and radiative lifetime of the a3Π0+ ↔ Χ1Σ0++ transition are calculated. The feasibility of laser cooling of TlBr molecule is analyzed by comparing with the thallium compounds and the bromides of the group-IIIA.