Theory of oriented symmetric-top molecule beams: Precession, degree of orientation, and photofragmentation of rotationally state-selected molecules

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.451821· OSTI ID:5657771

Choi, S E; Bernstein, R B

A theoretical study of the properties of rotationally state-selected symmetric top molecules has been carried out. Quantum mechanical and classical calculations are presented for the orientational probability density function P/sub J/KM( rho), characterizing the molecular precessional motion for various rotational states Vertical BarJKM> in terms of the degree of orientation rho (equivalentmu-circumflexxE) of the dipole moment ..mu.. in a (weak) electric field E. For all J>0, the breadths of the quantum mechanical distributions P/sub J/KM( rho) are significantly greater than those of the classically calculated ones P/sub cl/( rho). Their first moments, i.e., < rho>equivalentKM/(J/sup 2/+J), are, of course, identical. P( rho) is, in principle, directly observable through measurements of polarized laser-induced photofragmentation of oriented molecule beams. Expressions are derived to analyze experimentally observable angular distributions of photofragments. It is shown that I/sub J/KM/I/sub J/K = 2P/sub J/KM( rho), where I/sub J/KM and I/sub J/K are the photofragment intensities from oriented (JKM) and unoriented (JK) state-selected beams, respectively.

• Research Organization: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90024
• OSTI ID: 5657771
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 85:1; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular &amp; Chemical Physics-- Beams &amp; their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALIGNMENT
ANGULAR DISTRIBUTION
BEAMS
DISTRIBUTION
ENERGY LEVELS
EXCITED STATES
MOLECULAR BEAMS
ORIENTATION
PROBABILITY
ROTATIONAL STATES