Physical Chemistry Seminar – Truong-Son Nguyen

About the event

Trong-Son Nguyen, Graduate Student (Peterson Group)

Title: Actinide Ionization Potentials: Studying Trends of Late Actinides

Abstract: The f-block metals, namely the actinides, are generally known for their rich chemistry due to their close-lying (n-1)d, (n-2)f, and ns orbitals. Due to this dense nature of the valence space, and due to how the 5f orbitals radially contract and decrease in energy rapidly (in comparison to nearby orbitals) across the periodic table from left to right, one can expect to discover new electronic behavior.

The Feller-Peterson-Dixon (FPD) method is a composite, computational approach that allows one to accurately calculate such physical quantities in a systematic way. Even without experimental data available for the specific systems examined, this process can be predictive; if needed, analogous systems with available data could be used to see if the results still make physical sense.

The focus of this talk will be on discovering surprising electronic behavior while calculating the ionization potentials (IPs) of the early-to-mid-actinides. Earlier, the ionization potentials up through the +VIII oxidation state of plutonium atom had been determined at the MRCI (multi-reference configuration interaction) level of theory, and where feasible, the CCSD(T) (coupled-cluster with singles, doubles, and perturbated triple excitations) level of theory as well. More recently, neptunium, americium, and curium ionization potentials were also addressed, and one may see that some of these actinides so far, particularly in the later oxidation states, do not behave according to chemical intuition.