CAREER: Towards an accurate and illuminating theory of weak interactions between open-shell systems

Auburn University, Auburn AL

Investigators

Abstract

Konrad Patkowski of Auburn University is supported by the Chemical Theory, Models, and Computational Methods program in the Chemistry division to develop a new approach to computing noncovalent interaction energies between open-shell systems - a multireference version of symmetry-adapted perturbation theory (SAPT). The unique feature of SAPT is its combination of high accuracy and interpretive power, the interaction energy is obtained as a sum of well-defined contributions corresponding to electrostatics, exchange repulsion, induction, and dispersion. Prof. Patkowski and his group extend the applicability of SAPT to interacting systems with significant static correlation that cannot be described by a single Slater determinant. The newly formulated methods are used to compute and interpret interaction energies involving atmospheric radicals, organic polyradicals, and small molecules adsorbed within metal organic frameworks. The NSF EPSCoR office is also supporting this research. The knowledge of interaction energies between molecules is critical for our understanding of molecular liquids and crystals, atmospheric reactions, interstellar molecules, and the structure and function of proteins. Similar interactions bind small molecules such as carbon dioxide in the porous environment of metal organic frameworks. Prof. Patkowski and his group develop new methods to compute interaction energies in a way that elucidates the underlying physics of the interaction. The understanding gained in this way helps design new frameworks that can be more effective in gas separation, in particular, in removing carbon dioxide from flue and exhaust gases so that it does not get released into the atmosphere. The new methods are implemented in an open-source computer code that is freely available to other researchers. In addition, Prof. Patkowski and his group are developing hands-on computational chemistry modules within the framework of the Auburn University Summer Science Institute, providing realistic research experience to gifted high-school students and enhancing their awareness of the careers in science.