Inherent Nodal Structures in Doubly-Excited Intrashell States of Atoms

Quantum mechanical systems are strongly constrained by symmetry. Consequently, inherent nodal surfaces are imposed on the wave functions. In this paper, the inherent nodal surfaces existing in the doubly-excited intrashell states of atoms have been investigated. The decisive effect of these surfaces on low-lying states has been demonstrated. The feature of the spectra has been explained.