Photoelectron Spectra Showing Relaxation Effects in the Continuum and Electrostatic and Chemical Influences of the Surrounding Atoms

Abstract

The lowest ionization energy ( I ) of a gaseous atom, molecule, or of a solid has very different and well-defined characteristics than ( I ) of the subsequent penultimate orbitals. Thus, the lowest ( I ) of a gaseous molecule can be determined as the threshold photon energy sustaining ionization and passage of current through the gas, and the lowest ( I ) of a solid can be found as the threshold photon energy for Einstein photoemission though such measurements are easier performed on metals than on nonconducting samples. In the gaseous molecules a distinction is made between adiabatic ionization energies allowing the internuclear distances to vary and vertical ionization energies keeping the internuclear distances invariant. The exchange integrals of the two-electron operator are important for the practical calculations on atoms and molecules by decreasing the total amount of interelectronic repulsion in the antisymmetrized Slater determinant relative to a simple Hartree product. Finally, the questions on the time scale of a given experimental technique strongly influence the opinion formed about the symmetry of a molecule or polyatomic ion.