Accession Number : AD0660610

Title :   RESEARCH DIRECTED TOWARDS THE STUDY OF FAR INFRARED ABSORPTION CONTOURS.

Descriptive Note : Final rept. 1 Feb 62-31 Jan 67,

Corporate Author : PROVIDENCE COLL R I DEPT OF PHYSICS

Personal Author(s) : Gora,Edwin K.

Report Date : JUL 1967

Pagination or Media Count : 51

Abstract : Research was directed towards the formulation and extension of mathematical and theoretical methods suitable to calculate frequencies, intensities, and shapes of far-infrared lines, in particular, of asymmetric rotor molecules. A previously formulated asymptotic method applicable to high J-low K asymmetric rotor levels was extended to angular momentum expectation values of higher order. A minimization procedure previously used in the theory of diatomic molecules was adapted to nonlinear triatomic molecules, and employed to derive formulas for centrifugal distorsion corrections of higher order in the angular momentum operators. A semi-classical treatment of vibrational anharmonic perturbations was formulated to supplement the minimization procedure. The development of these methods and procedures had been motivated by an analysis of SO2-absorption contours - line shape studies led to a phenomenological treatment describing simultaneously the transition from interruption to statistical broadening, and from Van Vleck-Weisskopf to Lorentzian broadening. Consideration of the 'duration of collisions' proved essential in this formulation. (Author)

Descriptors :   (*INFRARED SPECTROSCOPY, NUMERICAL METHODS AND PROCEDURES), (*MOLECULAR SPECTROSCOPY, THEORY), ABSORPTION SPECTRA, DIATOMIC MOLECULES, POLYATOMIC MOLECULES, FREQUENCY, INTENSITY, LINE SPECTRA, MOLECULAR ENERGY LEVELS, STATISTICAL DISTRIBUTIONS, SULFUR COMPOUNDS, DIOXIDES

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE