Vol. 27, issue 01, article # 4

Abstract:

It was shown that interaction potentials for the NH₃–Ar and NН₃–Не systems are determined ambiguously from the experimental data for the broadening coefficients γ of absorption spectral lines of NH₃ molecule. The different sets of model interaction potential given the same accuracy of calculation of coefficients γ for room temperature determine these coefficients for other temperatures in different ways. This difference is more visible for the NН₃–Не system. For NH₃–Ar system this difference becomes apparent for the lines with small value of rotational quantum number K, for K → J this effect decreases.

Keywords:

intermolecular potential, half-widths, NH3–Ar, NH3–He

References:

1. Leavitt R.P. Pressure broadening and shifting in microwave and infrared spectra of molecules of arbitrary symmetry: An irreducible tensor approach // J. Chem. Phys. 1980. V. 73. P. 5432–5450.
2. Kaplan I.G. Vvedenie v teoriju mezhmolekuljarnyh vzaimodejstvij. M.: Nauka, 1982. 311 p.
3. Buldyreva J., Lavrent’eva N.N., Starikov V.I. Collisional Line Broadening and Shifting of Atmosphyric Gase. A practical Guide for Line Shape Modeling by Current Semi-classical Approaches. London: Imperical College Press, 2010. 323 p.
4. Girshfelder Dzh.O., Kurtis Ch.F., Bred R. Molekuljarnaja teorija gazov i zhidkostej. M.: Izdatelstvo inostr. literatury, 1961. 929 p.
5. Starikov V.I. Noble gas broadening calculation for fundamental bands of H₂S // J. Comput. Methods in Sci. and Eng. 2010. V. 10, N 3–6. P. 599–608.
6. Starikov V.I. K raschetu temperaturnoj zavisimosti kojefficientov ushirenija vrashhatel'nyh linij pogloshhenija molekuly H₂S davleniem gelija // Optika atmosf. i okeana. 2012. V. 25, N 4. P. 301–306.
7. Solodov A.M., Starikov V.I. Helium-induced Halfwidths and Line Shifts of Water Vapor Transitions of the ν₁ + ν₂ and ν₂+ν₃ Bands // Mol. Phys. 2009. V. 107. P. 43–51.
8. Petrova Т.M., Solodov A.M., Starikov V.I., Solodov A.A. Measurements and calculations of He-broadening and -shifting parameters of the water vapor transitions of the  ν₁ + ν₂ + ν₃ band // Mol. Phys. 2012. V. 110, iss. 14. P.1493–1503.
9. Smith E.W., Giraud M., Cooper J. A semiclassical theory for spectral line broadening in molecules // J. Chem. Phys. 1976. V. 65. P. 1256–1267.
10. Dhib M., Bouanich J.P., Aroui H., Broquier M. Collisional broadening coefficients in the ν₄ band of NH₃ perturbed by He and Ar // J. Mol. Spectrosc. 2000. V. 202. P. 83.
11. Dhib M., Echargui M.A., Aroui H., Orphal J., Hartmann J.M. Line shift and mixing in the ν₄ and ν₂ band of NH₃ perturbed by H₂ and Ar // J. Mol. Spectrosc. 2005. V. 233. P. 138–148.
12. Dhib M., Echargui M.A., Aroui H., Orphal J. Shif-ting and line mixing parameters in the ν₄ band of NH₃ perturbed by CO₂ and He: Experimental results and theoretical calculations // J. Mol. Spectrosc. 2006. V. 238. P. 168–177.
13. Starikov V.I. Raschet relaksacionnyh parametrov perekryvajushhihsja linij molekuly ammiaka v sluchae ih ushirenija davleniem argona i gelija // Optika i spektroskopija. 2013. V. 14, N 1. P. 1–11.
14. Khristenko S.V., Maslov A.I., Shevelko V.P. Molecules and their Spectroscopic Properties. Berlin: Springer, 1998. 174 p.