Electronic Structure Theory for Spin-Forbidden Reaction Dynamics
Abstract
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. Target chemical applications include the prediction of the energetics of C-H oxidative addition in transition metal catalysis and gas-phase spin-forbidden reactions that exhibit the so-called two-state reactivity mechanism, such as the FeO+ + H2 reaction. All of the programs will be implemented in the BAGEL package, a full-fledged electronic-structure program designed for large-scale parallel computer hardware. The programs will be distributed openly under the GNU General Public License to enable collaborations within the AFOSR program and beyond.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 11, 2018
- Source ID
- FA95501810252
Entities
People
- Toru Shiozaki
Organizations
- Air Force Office of Scientific Research
- Northwestern University
- United States Air Force