Accurate Calculations in Heavy Atom Chemistry
Speaker: Mike Schmidt
Abstract: Chemistry has always been an experimental science, but its guiding principles have come from the realm of physics since the discovery of the nucleus, electrons, and the quantum mechanics that rules them. The field of quantum chemistry has matured to the point where computations can assist in understanding results form the laboratory, or even in suggesting future experimental work. To obtain results of sufficient accuracy, the theoretical chemist must use a large basis set to expand the orbitals and a sufficiently sophisticated many-electron wavefunction. However, when a heavy element is involved, a third complication arises, namely relativity. This seminar will present a computational complement to results obtained in the Yang Laboratory at the University of Kentucky for a Cerium containing molecule. The talk is intended to teach students the connection between the Schrodinger equation and the relativistic Dirac equation. The correct physics of the latter can be approximated in a normal quantum chemistry program solving the former equation by modification of one electron integrals. The presentation of relativistic quantum mechanics will be qualitative - no prior understanding of Einstein is necessary!