ASSIGNMENT OF SOME PROMINENT FEATURES IN THE EXPERIMENTAL K-SHELL EXCITATION SPECTRUM OF METHANE BY MEANS OF CI CALCULATIONS

Term values and dipole transition probabilities of the vertical electronic transitions to low-lying K-shell excited states of methane which have recently been calculated by the configuration interaction method are compared to a well-resolved experimental K-shell excitation spectrum published by Tronc et al. In contrast to previous theoretical studies our calculation procedure accounts for a large amount of the electron correlation. The calculated vertical transitions are in good accordance with some prominent features of the experimental spectrum. A new assignment is proposed for the feature at 288.70 eV excitation energy in the experimental spectrum.