Marcel Nooijen

Born June 2, 1963 in Veghel, The Netherlands

Professor of Chemistry, University of Waterloo, Canada

Email:nooijen@uwaterloo.ca
Web: external link

Medal of the International Academy of Quantum Molecular Science (2003), Member International Academy of Quantum Molecular Science (2016)

Author of:

Important Contributions:

• Coupled Cluster Green�fs Function (PhD): A recursive diagrammatic approach to the single particle Green�fs function without use of the intermediary self-energy or Dyson equation. The approach provides an alternative take on equation of motion coupled cluster methods for ionization potentials and electron affinities, and Feynman-Dyson amplitudes.
• Similarity Transformed Equation of Motion Coupled Cluster (STEOM-CC) approach to excited states, as well as doubly ionized and doubly attached states. The approach uses a sequence of two many-body similarity transformations (normal ordered exponentials) to approximately decouple primary states of interest from the rest of the Hilbert space.
• Construction of diabatic vibronic models, using EOMCC, and their application to simulations of molecular spectroscopy.
• Development with Dominika Zgid of spin-adapted DMRG-SCF approach.
• Multireference Equation of Motion Coupled Cluster (MR-EOMCC). Using a sequence of Many-Body similarity transformations and the use of Kutzelnigg-Mukherjee normal ordering for a multiconfiuational reference defines a transformed Hamiltonian. Hundreds of excited states can be obtained from subsequent diagonalization over a compact CAS+1h+1p space. The method is implemented in both the ACESII and ORCA packages using automated computer code generation.
• Introduction of generalized extensivity, a conjecture regarding exactness of parameterization using two-body cluster operator, elimination of Coulombic singularities using similarity tranformations, work on generalized Wick�fs theorems for multiconfigurational reference.