Grant: Discovery Grants Program - Individual

Innovations from Canada have revolutionized the quantum information (QI), electric-vehicles (EV), solar cells (SC), and light-emitting diodes (LED) industries and have been central in positioning Canada as an international leader in these high-tech fields. Further advances in these fields are unfortunately hindered by the small arsenal of applicable materials. The performance of the materials is determined by interactions between nuclear vibrations, electronic motions, and electronic spins. They are responsible for quantum information transmission, energy, and charge transfer in the materials. These interactions are called vibronic and spin-vibronic couplings. To further the developments in these important industries, accurate simulations of the two couplings are indispensable. However, current simulation methods are inadequate in accuracy and efficiency to provide reliable and useful results to meet the needs. The proposed research program includes two methodological development projects (Projects 1 and 2) and three application-oriented projects (Projects 3-5) that employ those newly developed methods. In Project 1, we will derive the first unified Hamiltonian formalism for all vibronic and spin-vibronic Hamiltonians. After nine decades of intense research of the two couplings, such an important mathematical weapon is still missing. We will fill this gap of knowledge. In Project 2, we will develop an embedding protocol based on multireference density functional theory and Green's Function. The protocol will have a good compromise between accuracy and efficiency. It will be a powerful tool for excited state quantum chemistry calculations of local impurities in solids. Such impurities are often responsible for the optoelectronic properties of functional materials. We will then use the new methods to: (Project 3) investigate color centers, which is an important type of materials for quantum emitters. We will also design new cost-effective materials to replace the current mainstream diamond-based color centers; (Project 4) investigate lithiation in lithium-ion battery cathodes, with the objective to quench the Jahn-Teller distortion in the charge/discharge cycles, and then to elongate the lifetime of the batteries; (Project 5) investigate exciton generation, charge separation, and charge migration in perovskites, with the objective to design new materials with enhanced energy conversion efficiency in the perovskite-based photovoltaic devices and LED devices. The methodological advances in Projects 1-2 will enhance Canada's academic profile and train the next generation of theoretical chemists for the country. The new materials and trained personnel of Projects 3-5 will immediately impact QI, EV, SC, and LED industries and contribute to continuous economic growth of Canada.