Time-evolution of molecular states in electronically diabatic phenomena

Journal Article · Tue Dec 01 00:00:00 EST 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.463439· OSTI ID:6997686

Fernandez, F M; Micha, D A ^[1]

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1. Quantum Theory Project, Departments of Chemistry and of Physics, University of Florida, Gainesville, Florida 32611 (United States)

We describe the propagation in time of quantal molecular states for electronically diabatic phenomena involving the coupling of two or more electronic states. We first show how the time propagation of a wave packet can be broken up into several stages corresponding to regions through which the wave packet moves with or without electronic couplings. This is done with a generalization of the interaction picture procedure recently shown to be quite efficient for numerical work. We next consider the propagation of total molecular states in regions with couplings by using sequences of transformations between adiabatic and diabatic electronic representations for a finite number of coupled electronic states. This requires the introduction of a general and efficient way of transforming between the two representations, that is the main concern of this contribution. The transformation is constructed using Lie-algebraic methods; it leads to simple expressions suitable for computations, and contains as a special case the coupling of two electronic states. The propagation in time through the electronically diabatic region is described using a split-operator propagator procedure suitable for electronically diabatic phenomena. We concentrate on only one molecular variable, which could be a bond distance or a bond angle, to focus on the construction of the adiabatic--diabatic transformation.

• DOE Contract Number: FG05-87ER60517
• OSTI ID: 6997686
• Journal Information: Journal of Chemical Physics; (United States), Vol. 97:11; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
MOLECULES
ENERGY LEVELS
COUPLING
DIABATIC APPROXIMATION
ELECTRONS
ENERGY-LEVEL TRANSITIONS
HAMILTONIANS
LIE GROUPS
QUANTUM MECHANICS
TIME DEPENDENCE
WAVE PACKETS
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MATHEMATICAL OPERATORS
MECHANICS
QUANTUM OPERATORS
SYMMETRY GROUPS
664100* - Theory of Electronic Structure of Atoms & Molecules- (1992-)