Transition Spectra in the Vibrational Quasicontinuum of Polyatomic Molecules:  Raman Spectra of Highly Excited UF₆ Molecules

Abstract

Spontaneous Raman spectra of highly excited UF 6 molecules in the vicinity of the mode ν 1 are studied. The spectra measured are interpreted within the framework of the model suggested, which presumes the dominant role of statistical inhomogeneous broadening in the formation of transition spectra in the vibrational quasicontinuum. A good agreement is obtained between the theoretical and experimental spectra of UF 6 molecules heated to T vib ) 1320 K. The relationships are found between the vibrational energy of the UF 6 molecule and the main parameters of its Raman transitions in the neighborhood of the frequency of the mode ν 1 , such as the intensity, width, and maximum positions of their profiles.

Intramolecular vibrational redistribution: from high-resolution spectra to real-time dynamics

“…The simplest approach consists in using IR MPE (see Section 1.3) and measuring the spectrum after a time delay ensuring the establishment of the Boltzmann distribution. This method was used for measuring the absorption spectrum in one of the bands of the C 6 F 12 molecule [312], the n 3 IR MPE spectrum of the SF 6 molecule [313], the n 1 Raman spectrum of the same molecule [314,315], and the n 1 Raman spectrum of the UF 6 molecule [316]. However, in some papers spectra were measured for narrow vibrational distributions.…”

Спектроскопия Квантовых Биений В Системе N Одинаковых, Близко Расположенных Атомов. I. Случай N=2

“…Вполне вероятна ситуация, когда эта большая ширина обусловлена в основном влиянием на частоту перехода распределением по числам заполнения в фононной подсистеме. Такое уширение (даже в одиночном сложном объекте) аналогично так называемому статистическому неоднородному уширению в колебательно-возбужденных многоатомных молекулах, исследованному теоретически и экспериментально в работах [12][13][14][15]. Если так, то можно рассчитывать на различные методы исключения спектральной неоднородности.…”