Experimental and theoretical shakeup studies. III. The 1<i>s</i> shakeup in CH4, NH3, and H2O

Abstract

The core 1s level x-ray photoelectron spectra of CH4, NH3, and H2O have been recorded to high statistics. Several satellite peaks are resolved in each spectrum. The shakeup peaks are assigned with the aid of Xα–SW calculations. A comparison of the ten electron hydride MO diagrams with the neon atomic energy levels reveal the Rydberg character of the empty excited state orbitals. The shakeup transitions in the respective molecules can also be interpreted from atomic models constructed from the experimental shakeup spectrum of neon. The 2p contribution to the total relaxation energy is calculated from a spectral weight analysis of the shakeup spectra.