Multiconfiguration Pair-Density Functional Theory for Complex Chemical Systems

Laura Gagliardi and Donald G. Truhlar of the University of Minnesota are supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to develop a theory that enables high-accuracy calculations on chemical reactions on large systems. This method, Multi-Configuration Pair-Density Functional Theory (MC-PDFT), was recently introduced as a practical way to treat reactions where bonds are breaking, situations where electrons are excited, or systems that contain transition metals. All of these examples involve interactions among multiple electronic states, that are challenging problems for many other high accuracy methods in quantum chemistry. MC-PDFT is being broadly applied to systems in photochemistry, catalysis, supramolecular chemistry, and spectroscopy and thus has relevance in advanced manufacturing, renewable energy, and the chemical industry. In addition to the wide impact the method may have on the computational chemistry community, a broader impact of this proposal is the combination of expertise of two investigators, which allows students to benefit from a wider range of ideas and thereby contributes to well-rounded career preparation. Both investigators encourage women to enter scientific careers which contributes to a more diverse scientific workforce.

Laura Gagliardi and Donald G. Truhlar are developing Multi-Configuration Pair-Density Functional Theory (MC-PDFT), a recent method for inherently multiconfigurational systems, that combines DFT with multiconfiguration wave functions. Their work is extending the theory in three directions. First, they are developing methods to calculate analytic gradients for state-averaged calculations, a feature that is important to enable exploration of excited states. Second, they are developing a state interaction method for treating multiple electronic states in regions near conical intersections. Third, they are incorporating MC-PDFT into additional software and are applying the methods to transition metal systems and excited states. One broader impact of this proposal is to combine the expertise of two investigators to allow students to benefit from a wide range of ideas, thereby contributing to well-rounded career preparation. Other important broader impacts stem from the technological importance of the research subjects chosen, especially for health, the material needs of society, industrial competitiveness, and defense.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.