In this project funded by the Chemical Structure Dynamics and Mechanism (CSDM-A) Program of the NSF Chemistry Division, Professor Boldyrev explores new frontiers for multicenter bonding. In high school and college chemistry classes, chemical bonds are typically presented as pairs of electrons shared between two atoms (a single pair produces a single bond, two pairs create a double bond, etc.). However, there are many cases where chemical bonds are formed through electrons being shared by multiple atoms (hence the name "multicenter"). Professor Boldyrev and his group have developed a theoretical model that takes into account both two- and multi-center chemical bonding. He and his group are now applying this model to explain the geometry and behavior of complex systems such as cluster molecules containing dozens of atoms, molecules dissolved in liquids, and molecules which have been excited by light. Chemical bonding is at the heart of chemical understanding, and is the basis for explaining why molecules and solids adopt a certain geometric structure, and why molecules or solids react with other molecules in a particular manner. Professor Boldyrev's computational approach is called Adaptive Natural Density Partitioning, or "AdNDP." AdNDP is currently used by 50 research groups around the world, and the Boldyrev group is continuing to make this program and its updates available to other scientists. The graduate students involved in this project are not only helping to advance the field of chemistry, but are also obtaining important skills in computer programming and software development, all of which are valuable assets in the technology industry.
This project is exploring new chemistry frontiers for the application of the AdNDP method and its solid-state adaptation (SSAdNDP). The topics being studied include chemical bonding in excited states of molecules and clusters, the interaction of solvated electrons and multiply charged anions with solvent molecules. The project seeks to understand the chemical bonding in novel three-dimensional (3D) chemical systems that have been synthesized under extremely high pressure. Such high-pressure compounds violate many conventional stoichiometries and chemical bonding. In such systems, chemical bonding cannot be rationalized on the basis of a Lewis model alone. This project continues to benefit from collaborations with experimentalists (Professors Kit Bowen at Johns Hopkins, Lai-Sheng Wang at Brown University, Michael Heaven at Emory University, and Zhong-Ming Sun at the Chinese Academy of Sciences) who are providing experimental data on newly made clusters (0D species), as well as new 1D-, 2D- and 3D-materials. The broader impacts of this work include potential societal benefits of the AdNDP and SSAdNDP methods for the rational design of new materials, and for application in chemical education. These methods and the software developed under the support of Chemical Structure Dynamics and Mechanism (CSDM-A) Program of the NSF Chemistry Division are being developed for use in classes such as general chemistry, computational chemistry, quantum chemistry, advanced inorganic chemistry, nanotechnology, and materials chemistry.
