Nodal Surfaces in Molecular Wave Functions

One electron molecular orbitals for mobile electrons, subject to the potential energy of a molecular skeleton, are considered. If the atoms are far apart, the orbitals can be built up exactly from $2p$ atomic wave functions. The molecule in natural size is formed by adiabatic approach. It is shown that all the nodal surfaces reach into infinity, if the atoms are all alike, but that closed nodal surfaces may exist, if they are not. It is proved that the number of electrons inclosed in nodal surfaces is invariant against adiabatic change. Nodal surfaces for antisymmetrized molecular orbitals are then discussed.