The main objective of this project is to use ab initio molecular orbital calculations combined with Franck-Condon Factor (FCF) calculations to simulate electronic and photoelectron spectra of triatomic and tetraatomic molecules. This is done to support the experimental work in the group to achieve vibrational assignments of the observed bands.

Calculations of the Structure and Stability of Molecular Complex Ions of Importance to Atmospheric Chemistry

Ab initio calculations are used to calculate the minimum energy geometries and vibrational frequencies of ionic molecular complexes. These species have been shown to be of great importance in the understanding of the chemistry involved in the upper atmosphere. Use of the calculated quantities with simple statistical mechanical techniques allows the calculation of  thermochemical properties, such as the enthalpy, entropy, free energy and equilibrium constants for various reactions. It has been demonstrated that in most cases, accuracy equal to that from experimental measurements is achievable. It is hoped to extend the studies from 1:1 bonded complexes such as NO⁺.H₂O to larger 1:n complexes. It has been shown that intracomplex chemistry can occur in the larger complexes, and this is an area of great relevance to the chemistry of the upper atmosphere.

Further to the work on NO⁺(H₂O)_n, related studies are proposed on O₂⁺(H₂O)_n and ion molecule reactions of atmospherically importance such as:

O₂^- + CH₂Cl₂    and    OH^- + CH₂F₂.