Relaxation of rotational angular momentum of polar diatomic molecules in simple liquids

Journal Article · Thu Mar 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.032501· OSTI ID:20982298

Padilla, A; Perez, J ^[1]

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1. Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38204 Tenerife (Spain)

The relaxation processes of rotational angular momentum of polar diatomic molecules diluted in simple liquids are analyzed by applying a non-Markovian relaxation theory to the study of the binary time autocorrelation function of the angular momentum. This non-Markovian theory was previously applied to the study of the infrared and Raman spectroscopy, and also to the analysis of the rotational energy relaxation processes. We have obtained non-Markovian evolution equations for the two-time j-level angular momentum correlation components involved in the angular momentum correlation function. In these equations, the time-dependent angular momentum transfer rates and the pure orientational angular transfer rates are given in terms of the binary time autocorrelation function of the diatomic-solvent anisotropic interaction. The non-Markovian evolution equations converge to Markovian ones in the long time limit, reaching the angular momentum transfer rates in the usual time-independent form. Alternative time scales for the angular relaxation processes, relative to the individual rotational processes as well as to the global decay correlations, are introduced and analyzed. The theory is applied to the study of the angular momentum relaxation processes of HCl diluted in liquid SF{sub 6}, a system for which rotational energy relaxation and infrared and Raman spectroscopy was previously analyzed in the scope of the same theory.

• OSTI ID: 20982298
• Journal Information: Physical Review. A, Vol. 75, Issue 3; Other Information: DOI: 10.1103/PhysRevA.75.032501; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
ANGULAR MOMENTUM TRANSFER
ANISOTROPY
CORRELATION FUNCTIONS
CORRELATIONS
DECAY
HYDROCHLORIC ACID
INFRARED SPECTRA
INTERACTIONS
LIQUIDS
MARKOV PROCESS
MOLECULES
ORIENTATION
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RELAXATION
ROTATIONAL STATES
SULFUR FLUORIDES
TIME DEPENDENCE