Studies On Molecular Dynamic Parameters And Resonant States Based On Structure Calculation Method

With the light source technology progress,rapid development has been made for the experimental and theoretical research on atomic and molecule physics.The exper-imental benchmark of dynamic parameters can be determined accurately by the x-ray scattering methods based on the third generation syncrotron radiation.Furthermore,the behaviors of atoms and molecules can be manipulated and controlled under the scale of femtosecond based on the free electron laser.The accurate squared form factors mea-sured by the x-ray scattering technique can reveal the behavior s of the wave functions of the ground and excited state in different spacial scale,while the dynamic behaviors of the metastable states of atoms and molecules can be explored by the free electron laser,and the interesting phenomena such as ICD have been observed.In principle,the accuracy of the calculated dynamic parameters of atoms and mole-cules under the first Born approximation?FBA?depends only on the accuracy of the structure calculation.Previous experimental results demonstrated that the forst Born approximation is valid for the scattering between x-ray and atoms?He,Ne,Ar ect.?.But for the scattering between x-ray and molecules,the validity of the first Born approxi-mation is unknown.At the same time,further testing of the accuracy of the structure calculation method based on the Born-Oppenheimer approximation is needed.There-fore,the x-ray scattering experiments on molecules and the corresponding theoretical calculation are required to verify the validity of the FBA and to evaluate the accuracy of the molecule structure calculation method.For resonant states,the method for the bound state calculation can also be used with some special treatment because of the partial lo-cality of its wavefunction.There are many molecule structure calculation methods,and the "multi-reference single and double excitation configuration interaction"?MR-SDCI or MRCI?method is employed in this thesis to calculate the structures of bound states,and is expanded to the complex region and combined with the "complex coordinate rota-tion method"?CRM?and the "complex absorption potential"?CAP?method to calculate the atom and molecule's resonant and ICD states.Details are as follows:?1?Use MRCI method to calculate the electronic structure of H₂ and N₂,and cal-culate the corresponding elastic and inelastic dynamic parameters within the first Born approximation.At the same time,use the x-ray scattering method to measure the vibra-cally resolved dynamic parameters of N₂ between 12-13.3eV excitation energy range.For simple system such as H₂,the calculation accuracy of the non-relativistic assymp-topic energy are very high,and the calculated dynamic parameters are in good agreement with the x-ray scattering experimental results.For the complecated system such as N₂,the calculated dynamic parameters are also in good agreement with the x-ray scatter-ing experimental results,and it is found that the FBA are not reached for the medium and high energy electron impact experiments.These results demonstrate that the FBA is valid for x-ray scattering with molecule,and extend the usable range of x-ray method as benchmark data.On the other hand,the difference between the calculated and measured?x-ray scattering?dynamic parameters of H₂ seems unusual,there may be considerable physical reasons behind the difference;?2?Develop the CRM/CAP + DVR method to calculate the one-dimentional rovi-brational resonant states of diatomic molecules.The resonant energy and autodissocia-tion rate of the rovibrational resonant states can be accurately determined through this method.The rovibrational autodissociation state of Cu₂^-and LiH^-are calculated with this method.For Cu₂,the autodissociation rates calculated with CRM/CAP + DVR method differ by an order of magnitude with the ones calculated with the WKB approx-imation method.This means the WKB approximation does not suit for heavy particles.The calculated resonant energy and width of LiH-are in good agreement with the ones calculated with quantal molecular orbit close coupling?QMOCC?method.These two methods tested each other perfectly.Moreover,the present CRM/CAP + DVR method can offer the corresponding rovibrational quantum numbers for each resonant peaks;?3?The Feshbach resonant states of atoms and molecules are calculated with CRM+MRCI method successfully.Through the calculation of Nq+?q=2-5?,the appropriate ba-sis set choosing rule is groped,and the energies and widths of 28 resonant Auger states are obtained.The present results are in good agreement with other experimental and the-oretical results available,and the spin-allignment auger rate rule is veryfied.The ICD rates of He₂⁺ are calculated with the CRM + MRCI method.Relative to other calcula-tion,in this thesis,smaller basis set and less calculation resource is used,but equivalent accuracy is reached.