Utility of Gaussian-Type Orbitals in Molecular Collisions: Electronic Excitation of the First Positive System of the Nitrogen Molecule

Abstract

The use of gaussian-type orbitals (GTO) as basis sets of electronic wave functions of molecules for calculating electron-collision excitation cross sections is discussed. A test calculation of the electron excitation cross section of the 2p state of atomic hydrogen at 60-1000 eV in which the hydrogenic wave functions were expressed as linear combinations of GTO indicates that an expansion of the is wave function by six GTO's and the 2p by four GTO's gives quite accurate results. Methods for evaluating the multicenter integrals which appear in the expressions of electron-excitation cross section (by the Born-type approximation) of diatomic molecules are described. Cross sections of direct electron excitation of the B(3)II(g) state (the first positive bands) of the N(2) molecule are calculated by this scheme, and the results are in good agreement with experiments.