Non-Born-Oppenheimer path in anti-Hermitian dynamics for nonadiabatic transitions

Journal Article · Tue Feb 14 04:00:00 EST 2006 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2167648· OSTI ID:20783224

Takatsuka, Kazuo ^[1]

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1. Department of Basic Science, The University of Tokyo, Komaba, 153-8902 Tokyo (Japan)

A serious difficulty in the semiclassical Ehrenfest theory for nonadiabatic transitions is that a path passing across the avoided crossing is forced to run on a potential averaged over comprising adiabatic potential surfaces that commit the avoided crossing. Therefore once a path passes through the crossing region, it immediately becomes incompatible with the standard view of 'classical trajectory' running on an adiabatic surface. This casts a fundamental question to the theoretical structure of chemical dynamics. In this paper, we propose a non-Born-Oppenheimer path that is generated by an anti-Hermitian Hamiltonian, whose complex-valued eigenenergies can cross in their real parts and avoid crossing in the imaginary parts in the vicinity of the nonadiabatic transition region. We discuss the properties of this non-Born-Oppenheimer path and thereby show its compatibility with the Born-Oppenheimer classical trajectories. This theory not only allows the geometrical branching of the paths but gives the nonadiabatic transition amplitudes and quantum phases along the generated paths.

• OSTI ID: 20783224
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 6 Vol. 124; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BORN-OPPENHEIMER APPROXIMATION
CHARGE EXCHANGE
ENERGY LEVELS
HAMILTONIANS
REACTION KINETICS
SEMICLASSICAL APPROXIMATION
SURFACES
TRANSITION AMPLITUDES