Minimalistic Descriptions of Nondynamical Electron Correlation: From Bond-Breaking to Transition-Metal Catalysis

CASPT3;CASPT2;Multi-reference;DFT;CASSCF;Transition-metal;Bond-breaking;Theory;Electronic structure

Sears, John Steven ; Chemistry and Biochemistry

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: CASPT3;    CASPT2;    Multi-reference;    DFT;    CASSCF;    Transition-metal;    Bond-breaking;    Theory;    Electronic structure;   

Others  :  https://smartech.gatech.edu/bitstream/1853/19807/1/sears_john_s_200712_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

From a theoretical standpoint, the accurate description of potential energy surfaces for bond breaking and the equilibrium structures of metal-ligand catalysts are distinctly similar problems. Near degeneracies of the bonding and anti-bonding orbitals for the case of bond breaking and of the partially-filled d-orbitals for the case of metal-ligand catalyst systems lead to strong non-dynamical correlation effects.Standard methods of electronic structure theory, as a consequence of the single-reference approximation, are incapable of accurately describing the electronic structure of these seemingly different theoretical problems. The work within highlights the application of multi-reference methods, methods capable of accurately treating these near-degeneracies, for describing the bond-breaking potentials in several small molecular systems and the equilibrium structures of metal-salen catalysts. The central theme of this work is the ability of small, compact reference functions for accurately describing the strong non-dynamical correlation effects in these systems.