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High-Resolution Spectroscopy and Analysis of the n3/2n4 Dyad of CF4

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Presentation on theme: "High-Resolution Spectroscopy and Analysis of the n3/2n4 Dyad of CF4"— Presentation transcript:

1 High-Resolution Spectroscopy and Analysis of the n3/2n4 Dyad of CF4
Vincent BOUDON Institut Carnot de Bourgogne – UMR 5209 CNRS-Université de Bourgogne, 9 Av. A. Savary, BP 47870, F DIJON, France Alexandra DOMANSKAYA Institute of Physics, Saint Petersbourg University, , SAINT PETERSBOURG, Russia Christof MAUL Institut für Physikalische un Theoretische Chemie des Technischen Universität Braunschweig, D BRAUNSCHWEIG, Germany Robert GEORGES Institut de Physique de Rennes, UMR 6251 CNRS – Université de Rennes 1, 263 Av. Général Leclerc, F RENNES, France Justin MITCHELL Department of Physics, University of Arkansas, FAYETTEVILLE, USA

2 The CF4 molecule CF4 is a strong greenhouse gas (natural and anthropogenic origin) Global Warming Potential = 6500 (CO2 = 1), lifetime = 50,000 years Concentration = 75 pptv, annual increase = 1.6 % 1 2 3 4 A1 E F2 Stretching Bending Raman IR 909 cm-1 435 cm-1 1283 cm-1 631 cm-1 Point group Td

3 Contents Experimental details Theory
Simultaneous analysis of line positions Intensities Semi-classical study

4 I. Experimental details

5 Data used for the simultaneous fit
Static-cell spectra (Braunschweig and Rennes) Supersonic expansion jet spectrum (Rennes) MW data for n3–n3 (M. Takami et al., Mol. Phys. 85, 733–744 (1995))

6 II. Theory

7 Effective tensorial Hamiltonian
Polyad structure P0 P1 P2 Systematic tensorial development Coupled rovibrational basis Effective Hamiltonian and vibrational extrapolation

8 Effective Hamiltonian for CF4
Effective Hamiltonian for the Ground State (P0 polyad) Effective Hamiltonian for the v4 = 1 level (= P1 polyad) Effective Hamiltonian for v4 = 2 / v3 = 1 (= P2) polyad

9 III. Simultaneous analysis of line positions

10 Fit statistics

11 Overview of the n4 band

12 Detail in the n4 band

13 n4 band : fit residuals for line positions

14 The 2n4 band

15 Overview of the n3 band

16 Jet-cooled spectrum of the n3 band

17 n3/2n4 dyad: fit residuals for line positions

18 IV. Intensities

19 Dipole moment parameters
Fit of the proportionality coefficient between the experimental and simulated spectrum to find the dipole moment derivatives n4 : use of P and R branches n3 : R branch only, P branch is perturbed by 2n4 Rough estimation for 2n4

20 V. Semi-classical study

21 Semi-classical energy curves

22 Semi-classical vs. quantum levels
See talk RJ06

23 Spherical Top Data System
The STDS database Spherical Top Data System • Molecular parameter database • Calculation and analysis programs • XTDS : Java interface NB : CF4 results included in HITRAN 2008


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