The ab initio geometries of a survey of 12 valence electron tri-molecules in their ground and first excited states are presented. We compared calculated geometry changes upon excitation to predictions based the HAB Walsh diagram and found that whether a molecule will obey the Walsh diagram depends on the identity of the central atom. For example, HNO and HCF are calculated to follow the HAB Walsh diagram, but if the central atom was P or As, the molecules do not follow the Walsh diagram. A general rule on the central atom identity is presented. Walsh-type diagrams, made by plotting orbital energies as a function of angle, are presented for several molecules that do and do not follow the original HAB Walsh diagram. Several other calculations were attempted to try to explore the discrepancies between the Walsh diagram and calculated geometry changes.

Trends in the calculated geometries of the lowest two electronic states of 12 valence electron triatomic HAB molecules

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.