ELECTRONIC EXCITATION OF FORMALDEHYDE BY LOW-ENERGY ELECTRONS - A THEORETICAL-STUDY USING THE COMPLEX KOHN VARIATIONAL METHOD

We report results of a fully ab initio treatment of electronic excitation in a polyatomic molecule by electron impact. We have calculated total and differential cross sections for exciting the two lowest (n*)1,3A2 excited states of H2CO for collision energies between 5 and 20 eV. The calculations were carried out in a three-state close-coupling approximation using the complex Kohn variational method. The absence of any backward peaking in the cross sections calculated for the A23 state is reminiscent of a rigorous selection rule for + - transitions in linear molecules. However, with no experimental studies available for comparison, the present results must be regarded as predictive. © 1990 The American Physical Society.