Quantum phase space theory for the calculation of v{center_dot}j vector correlations

Conference · Sat Jul 01 04:00:00 EDT 1995

OSTI ID:86979

Hall, G E ^[1]

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1. Brookhaven National Lab., Upton, NY (United States). Dept. of Chemistry

The quantum state-counting phase space theory commonly used to describe barrierless dissociation is recast in a helicity basis to calculate photofragment v{center_dot}j correlations. Counting pairs of fragment states with specific angular momentum projection numbers on the relative velocity provides a simple connection between angular momentum conservation and the v{center_dot}j correlation, which is not so evident in the conventional basis for phase space state counts. The upper bound on the orbital angular momentum, l, imposed by the centrifugal barrier cannot be included simply in the helicity basis, where l is not a good quantum number. Two approaches for a quantum calculation of the v{center_dot}j correlation are described to address this point. An application to the photodissociation of NCCN is consistent with recent classical phase space calculations of Cline and Klippenstein. The observed vector correlation exceeds the phase space theory prediction. The authors take this as evidence of incomplete mixing of the K states of the linear parent molecule at the transition state, corresponding to an evolution of the body-fixed projection number K into the total helicity of the fragment pair state. The average over a thermal distribution of parent angular momentum in the special case of a linear molecule does not significantly reduce the v{center_dot}j correlation below that computed for total J = 0.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 86979
• Report Number(s): BNL--61928; CONF-950793--5; ON: DE95014450
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANGULAR MOMENTUM
CALCULATION METHODS
CYANOGEN
DISSOCIATION
ENERGY-LEVEL TRANSITIONS
HELICITY
PHASE SPACE
PHOTON-MOLECULE COLLISIONS
ROTATIONAL STATES
VECTORS
VIBRATIONAL STATES