Electron impact excitation of molecules: Calculation of the cross section using the similarity function method and ab initio data for electronic structure

The electron impact excitation cross section of dipole-allowed transitions of diatomic molecules has been evaluated using the similarity function method combined with ab initio electronic structure calculations. In accordance with the similarity function method the excitation cross section is expressed through the oscillator strength of the transition and some universal function of the reduced incident electron energy. The necessary characteristics of molecular terms involved are determined through ab initio electronic structure calculations using the multireference configuration interaction technique or relativistic multipartitioning many-body perturbation theory. Comparison of results of specific calculations performed for CO and NO with available experimental data and comprehensive quantum-mechanical calculations shows a reasonable agreement.