Theoretical Analyses Of Slow High Charge Ions-molecules Collisions

In recent years, large molecules have been studied when they collide with kinds of slow high charge ions. It brings much progress to both medicals and bio-physics. Disappointing, theoretical model on collision between ions and molecules has not been found by physicist. This paper aims to develop a method so that transfer of electrons and structure of molecules can be calculated theoretically.Firstly, ab-intio method is adopted to calculating molecular orbital energies and valence bond of molecules collided. Here one kind of molecular orbital theory is introduced. It needs solving Roothaan equation which can be derived by expanding Hartree-Fock equation to molecular systems.Secondly, Molecular Columbic over Barrier Model is expanded so that it can be used to simulate ions-molecules collision systems. With atoms' orbital vanishing, molecular orbital dominates the calculation and can be worked out using ab-initio method. The expanded MCBM is a three-dimensional model that is a developed one-dimensional MCBM by averaging several characteristic incidences. And one method is introduced that the expanded MCBM simulates large molecules-ions collision system.Lastly, single capture cross section of H⁺ -H₂ collision is calculated, whichaccords with experiments and former theory results. Especially, changes to the cross section caused by electrons' spatial coordinates are analyzed and it shows the advantage of the method given above.