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The Breakdown Of Hund's Rule In Systems Of Fourfold Symmetry, Gordon A. Gallup
The Breakdown Of Hund's Rule In Systems Of Fourfold Symmetry, Gordon A. Gallup
Gordon Gallup Publications
The lowest energies of molecular systems with fourfold symmetry can violate Hund's multiplicity rule. We derive relationships between two electron integrals that in favorable cases allow one to predict when this will happen. These relationships result in a fairly simple inequality as a criterion. The systematics of the phenomenon are illustrated with a series of calculations on model systems consisting of hydrogen atoms. These are rings of three, four, five, six, seven, and eight members as well as octahedral and square planar arrangements. These show how the results and simple ideas of molecular orbital theory can be qualitatively modified when …
Nonorthogonal Configuration-Interaction Calculations Of Molecular States: The Low-Lying Molecular States Of Arhsup+ And Two-Electron Charge Exchange In Ar-H+ Collisions, Gordon A. Gallup
Gordon Gallup Publications
A nonorthogonal configuration-interaction procedure has been used to calculate adiabatic energy curves of ArH+. The basis functions are a mixture of typical molecular-orbital configurations and typical valence-bond (Heitler-London) configurations. This gives an economical description of the wave functions, allowing an easy tracing of various diabatic states through the adiabatic states and a clear identification of the asymptotic states. The results are used to rationalize the unexpectedly large production of Ar2++H- from collisions of H+ with Ar.