Born couplings in H/sub 2//sup +/, H/sub 2/, and H/sub 3/

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6291515

Sukumar, N

Some consequences of the Born-Oppenheimer separation of electronic and nuclear motions in molecules are investigated - in particular, the breakdown of this approximation in the vicinity of a Jahn Teller degeneracy (or near degeneracy) between electronic potential-energy surfaces. The gauge transformation properties of the so-called vector potential responsible for the molecular Aharonov-Bohm effect are discussed, and the possibility of a second-quantized description of radiationless nonadiabatic phenomena is pointed out. A prime candidate for a study of the breakdown of the Born-Oppenheimer approximation is the system of three hydrogen atoms in an equilateral geometry. Here, the Jahn-Teller degeneracy in the ground state is lifted only by spin-orbit interaction (a crude calculation shows that the resulting energy splitting is of the order of 10/sup -6/ Hartree). Different calculational methods were developed for determining the magnitudes of the interaction terms in the Hamiltonian representing the coupling between electronic and nuclear motions (the so-called Born couplings) and the programs tested on H/sub 2//sup +/ and H/sub 2/. A semiempirical scheme, based on the valence bond formalism, was used to calculate the Born couplings in H/sub 3/, for a range of molecular geometries. Results, the first on this system, show a high degree of internal consistency.

• Research Organization: State Univ. of New York, Stony Brook (USA)
• OSTI ID: 6291515
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
640305 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Theory-- (-1987)
74 ATOMIC AND MOLECULAR PHYSICS
BORN-OPPENHEIMER APPROXIMATION
CATIONS
CHARGED PARTICLES
ELEMENTS
HYDROGEN
HYDROGEN IONS
HYDROGEN IONS 2 PLUS
IONS
JAHN-TELLER EFFECT
MOLECULAR IONS
MOLECULES
NONMETALS