Electronic excitation of XH4 (X = C,Si,Ge,Sn,Pb) by electron impact

We calculate integral cross sections for the electronic excitation to the T-3(2) states of XH4 (X= C,Si,Ge,Sn,Pb) by electron impact. This is the lowest-lying excited state of these molecules. Our results were obtained with the Schwinger multichannel method with pseudopotentials at the two-state level of approximation. In the case of CH4 we compare our results with previous results of an all-electron calculation obtained at the same level of approximation, in which case we found an excellent agreement between the two calculations. Though these molecules are very similar, after discarding the cores, as the pseudopotential technique does, the inelastic cross sections are very distinctive and do not have a monotonic behavior with increasing proton number Z of the central atom.