Model space diabatization for quantum photochemistry

Journal Article · Sat Feb 14 04:00:00 EST 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4907038· OSTI ID:22416093

Li, Shaohong L.; Schmidt, Michael W.; Gordon, Mark S. ^[1]

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1. Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)

Diabatization is a procedure that transforms multiple adiabatic electronic states to a new representation in which the potential energy surfaces and the couplings between states due to the electronic Hamiltonian operator are smooth, and the couplings due to nuclear momentum are negligible. In this work, we propose a simple and general diabatization strategy, called model space diabatization, that is applicable to multi-configuration quasidegenerate perturbation theory (MC-QDPT) or its extended version (XMC-QDPT). An advantage over previous diabatization schemes is that dynamical correlation calculations are based on standard post-multi-configurational self-consistent field (MCSCF) multi-state methods even though the diabatization is based on state-averaged MCSCF results. The strategy is illustrated here by applications to LiH, LiF, and thioanisole, with the fourfold-way diabatization and XMC-QDPT, and the results illustrate its validity.

• OSTI ID: 22416093
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 6 Vol. 142; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOLE
CORRELATIONS
COUPLING
HAMILTONIANS
LITHIUM FLUORIDES
LITHIUM HYDRIDES
ORGANIC SULFUR COMPOUNDS
PERTURBATION THEORY
PHOTOCHEMISTRY
POTENTIAL ENERGY
SELF-CONSISTENT FIELD
STANDARDS
SURFACES