Using multiple computational methods in combination leads to fundamental insights in complex systems: where the complexity may arise either from the number of atoms or from strong electron correlation. Our research group tackles diverse problems in transition metal chemistry, f-element chemistry, and porous materials. Applications include controlling spin in transition metal complexes, contributing to solving the f-electron challenge, designing next-generation catalysts through collaboration, sustainable polymers, and more.

CASPT2 Molecular Geometries in Transition Metal Chemistry

Multiconfigurational electronic structures have been shown to arise in a wide variety of metal complexes. For transition metals, this phenomena manifests in metal-metal bonds, spin-crossover complexes, and single molecule magnets. We are interested in using methods such as the complete active space perturbation theory method (CASPT2) to study a wide variety of systems beyond DFT. Our work uses fully internally contracted (FIC)-CASPT2 analytical gradients implemented in the BAGEL program package, of which we are developers.

Improving Sustainable Polymers with Computational Insights

Within the NSF Center for Sustainable Polymers (NSF CSP), we perform computational modeling in combination with experiment to provide molecular-level insights to reaction mechanisms in order to guide the design of the next generation of catalysts. By means of a combination of density functional theory (DFT) and classical simulations, we address questions arising from experiments performed in the Center. We are currently collaboration with the Tolman group at Washington University in St. Louis, the Dauenhauer and Tonks groups at the University of Minnesota, and the Kalow group at Northwestern University.

Computational Modeling in f-element Chemistry

Our current work on the actinides focuses in two areas. The first focuses on understanding the role of the 5f and 6d orbitals in bonding in uranium complexes. Specifically, we are interested in uranium-arene interactions and are studying a series of complexes in collaboration with the Fortier group at the University of Texas El Paso. Using a combination of DFT and CASPT2 computations, we examine the role that covalent bonding, spin-orbit coupling, and the nature of multiple low-lying excited states play in determining experimental observations. The other core area of our group focuses on lanthanide complexes. We are interested in improving ligands in volatile lanthanide complexes. We are also interested in understanding the speciation and reactivity of lanthanides in solution.

Gas Adsorption, Separations, Reactivity, and Sensing in Nanoporous Materials

Nanoporous materials such as metal–organic frameworks (MOFs) and zeolites have been widely used for gas storage, separations, catalysis, and sensing applications. In our group, we are interested in cases where selectivity of guest adsorption can be obtained by tuning intermolecular interactions, where gas adsorption induced a change of spin-state in the material itself, or when a reaction can be improved due to confinement.