Molecular dynamics with nuclear quantum effects: bridging classical and quantum regimes

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

In this project funded by the Chemical Theory, Models and Computational Methods program in the Division of Chemistry, Professor Sophya Garashchuk, at the University of South Carolina, Columbia, is developing new theoretical methods to analyze the dynamics of molecular motion. This method combines the microscopic behavior of electrons in molecules, treated by quantum mechanics with the motion of the nuclei of the atoms treated by classical mechanics, following that of Isaac Newton. The quantum-mechanical treatment of electrons is important and crucial to understand chemical reactivity, optical, magnetic and other properties of molecules. More importantly these new methods will allow researchers to investigate larger systems such as nanomaterials. Potential applications include photovoltaic materials that convert light to electricity, movement of atoms and molecules through membranes, and isotopic separation. The scientific goal is to develop a practical methodology for systems of 10-200 atoms, which incorporates Nuclear Quantum Effects (NQEs) for certain nuclei or modes of motion (quantized vibrations, rotations), while they fully interact with the remaining classically-described nuclei. Drawing on the ideas from the quantum trajectory formulation of the Schrodinger equation, we will develop a trajectory-based theoretical framework of including NQEs selectively within a larger molecular environment, transform the concepts into computer codes and through simulations advance our understanding of molecular systems, such as those mentioned above, known to exhibit isotope and other NQEs. Broader educational goals are to train junior researchers in theoretical, computational chemistry, and high performance computing, to facilitate use of computational chemistry tools by experimental colleagues through formal teaching and collaborative projects, and to provide access and training in computational chemistry tools for undergraduate institutions in South Carolina.