Theoretical Investigation Of The Molecular Structure Of BeH~+ And The Radiative Processes In Be-X~+(X=H,D,T)Collisions

It is of great importance to study the molecular structure and spectra,as well as the ion-atom collisions processes.In the astrophysics studies,the molecular spectra can be used to determine the specie and abundance of various elements in the environment;There are also rich atomic and molecular processes in the plasma of the edge and divertor area in TOKMAK.The scattering cross sections and rate coefficients of these reaction processes are necessary atomic parameter in the plasma simulation,which play important role in studying the particle diffusion and energy transportation,as well as the plasma status diagnosis.BeH+ molecules exist in the stellar atmosphere and interstellar matter environment etc,as well as the edge and divertor plasma area in TOKMAK.Because of the importance of BeH+,in the present paper,the molecular structure and transition spectra of BeH+ molecule are studied and the radiative processes in Be-H+(D+,T+)collisions are investigated.There are mainly two parts included in the present study:1.The molecular structure and opacity calculations for BeH+.The multireference single and double excitation configuration interaction(MRDCI)method is used to calculate the adiabatic potentials and electronic wavefunctions for the four low-lying singlet electronic states,including three 1∑+ and one 1π states,based on which,the corresponding rovibrational energies and wavefunctions are computed,as well as the transition dipole moments and Einstein coefficients.Using these molecular structure data,the BeH+ opacities are computed for different temperature conditions,and the partition functions are provided for the temperature T in the range of 100 K-40000 K.2.The radiative collisions processes in Be-H+(D+,T+)collisions.Using the molecular structure obtained,the fully quantum optical potential method is used to study the radiative processes in Be-H+(D+,T+)collisions.In the present study,the radiative processes from the state C1∑+ corresponding to H++Be(2s2)at the asymptotic region,to the lowest three states are considered,namely C1∑+-X1∑+,C1∑+-A1∑+,C1∑+-B1π.For these reaction processes,the scattering cross sections for the radiative decay,radiative charge transfer and raditive association are obtained for the energy E in the range of 10-8 eV/u-10-1 eV/u.Furthermore,the isotope effects in the radiative collision processes are also studied.