Investigations Of Spectroscopic And Collisional Properties Of BeX~+(X=H,D,T)’s Low Excited Electronic States

With the progress of the experiments of International Thermonuclear Experimental Reactor,the materials related to the experiments have attracted the attention of the majority of scholars.Studies have shown that beryllium can be used as a wall material for the first side of a reactor in thermonuclear experiments.The European Union fusion center uses beryllium to improve the plasma performance and the beryllium has always been considered as the main candidate material for plasma veneer components in controlled thermonuclear reactor.The research of the spectral characteristics of the materials properties plays an important role in promoting the experimental progress.Diatomic molecule consists the basis of many substance systems,and the hydride molecule has important applications in the research of astrophysics,medical science,chemistry and biology.In recently years,the spin-orbit coupling effect of atoms and molecules has become one research focus in the field of atom and molecule structures.It is particularly important to properly understand and consider the coupling effect of electronic states caused by its splitting,which is not conducive to the spectral identification of photosynthesis,bioluminescence,or astrophysics,etc.In this work,potential energy curves of six electronic states（X¹Σ⁺,a³Σ⁺,A¹Σ⁺,b³Π,B¹Π,c³Σ⁺）corresponding to the first dissociation limit（Be⁺（²S）+X（²S））and the second dissociation limit（Be⁺（²P）+X（²S））of Be X⁺（X=H,D,T）are calculated using the internally contracted Multiconfiguration-Reference Configuration Interaction approach based on the consistent cc-p VQZ basis set.Based on the calculated potential energy curves,one-dimensional radial Schr?dinger equations are solved by LEVEL program.Consequently,the ro-vibrational constants,Franck-Condon factors and radiative lifetimes of the corresponding electronic states are obtained.In order to gain a deep understanding of the internal characteristics of the molecular ion Be X⁺,the spin-orbit coupling interaction is included in the calculations.Due to the atom mass in the present work is light,theΛ-Σcoupling is chosen.The spin-orbital coupling constants of b³Πand c³Σ⁺states are calculated on the basis of the calculation of Breit-Pauli operator,and they are 2.66 and 0.0044 cm^-1,respectively.The distributions of Boltzmann population of the X¹Σ⁺of Be H⁺are derived at the vibrational temperatures of 2500 K,5000 K,7500 K and 10000 K.Moreover,the spectra ofΔυ=-2（0-2,1-3）andΔυ=-3（0-3,1-4）bands in A¹Σ⁺-X¹Σ⁺system ranged from 285 nm to 340 nm at the rotational temperatures of 500 K,1000 K,1500 K and 2000 K are simulated at the vibrational temperature of 10000 K.The probabilities of radiative transition and collision transition between different molecular rotational energy levels are necessary for a more detailed analysis of the spectrum,but the quantum calculation of vibrational excitation cross sections is complex and time consuming.In this paper,we adopted the MOLSCAT computing software in the solving of the cross sections of collision transition between different rotational energy levels.The software constructed the coupled-channel equations of atom and molecules,and solves them by propagating the wave functions or log-derivative matrices outward from short range to the asymptotic region.And then the scattering matrix（S matrix）is calculated based on the scattering boundary conditions.The electronic system of the Be H⁺ion fromυ=0 toυ=8 between the rotational collision integral cross section are calculated.