In this proposed research, we seek to develop novel relativistic multireference electron correlation methods, such as relativistic multireference perturbation (CASPT2) and configuration interaction (MRCI), for accurately simulating spin-forbidden chemical reactions. Spin-forbidden reactions are ubiquitous in catalysis and in gas-phase small-molecule reactions. The proposed methods are based on the relativistic Hamiltonians that explicitly include spin–orbit coupling. The central hypothesis is that, for reactions that undergo almost quantitative spin inversion (often due to strong spin–orbit coupling that couple different spin states), one must use methods that are based on relativistic Hamiltonians so that spin–orbit coupling is included to infinite order. In the relativistic picture, the spin barriers for spin–forbidden reactions are expressed as simple transition states on the ground-state surfaces. Special emphasis is placed on the ability to predict molecular structures of equilibrium geometries and transition states; we will develop a program to compute the nuclear gradients and derivative couplings for relativistic CASPT2 to realize such computations.
|Effective start/end date||6/15/18 → 12/15/20|
- Air Force Office of Scientific Research (FA9550-18-1-0252 P00002)