Extending the method which was employed for CH 4, the energy spectra for photoabsorption and photoionization and those for excitation (including superexcitation) are calculated using ultraviolet photoelectron spectroscopy data for the respective molecules, NH 3, H 2O and HF, and oscillator strength data for their isoelectronic atom, Ne. A discussion of the classification of superexcited states is given. There are three possibilities for superexcitation: (1) that attributed to high-Rydberg states converging to the first ionization potential followed by a Jahn-Teller molecular distortion, (2) that attributed to excitation from inner orbitals, including both those cases followed by and those not followed by molecular distortion, and (3) that attributed to double excitation. From a comparison between calculations of the ionization efficiency curves and the experimental results, the present treatment is found to give reliable results.