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Dynamic coupling of intra- and intermolecular effective modes in H-bonded water clusters in the long-wavelength infrared rangeстатья
- Авторы: Belega E.D., Zakirov M.N., Vasilyev K.A., Chulichkov A.I., Novakovskaya Yu V.
- Журнал: Physical Review A
- Том: 110
- Год издания: 2024
- Издательство: American Physical Society
- Местоположение издательства: USA
- Первая страница: 1
- Последняя страница: 21
- Номер статьи: 062815
- DOI: 10.1103/PhysRevA.110.062815
- Аннотация: The method of effective modes is used for quantifying the dynamics of energy redistribution between different kinds of motions in water clusters upon their excitation within the long-wavelength infrared range <2000 cm−1. Three kinds of vibrations were considered, namely, radial and angular distortions of H bonds and bending vibrations of the molecules. Dynamics of the clusters (described in the Born-Oppenheimer approximation with the electronic problem solved at the MP2 level) was promoted by the initial excitation of particular kinds of motions or their combinations with the total activation energy per molecule in a range of 1.2–4.6 kcal/mol. Gross contributions of the different kinds of motion to the leading effective modes of clusters were determined as functions of time, which made it possible to estimate the dynamic coupling. The coupling of motions depends on the number of water molecules as well as on the activation energy and its initial distribution over particular degrees of freedom. The energy initially concentrated on radial distortions can be transferred directly to the angular distortions, and the corresponding mean dynamic coupling parameter reaches a maximum of 5.0 ×1011 to 6.0×1011s−1 at the initial kinetic energy per molecule ∼3.2–3.5 kcal/mol. It decreases with an increase in the flexibility of the cluster. When the energy is initially concentrated on the angular distortion modes, its relaxation toward the lower-frequency radial modes is usually indirect and requires the mediating role of bending vibrations whose temporary contribution to the dynamics can be as high as 25–30%. The angular-to-radial distortion coupling parameter is lower by nearly half than the radial-to-angular one. When angular distortions are initially activated concurrently with the bending vibrations, the prevailing energy relaxation channel is the activation of radial distortions. Upon the initial excitation of bending vibrations, the energy can be kept by the modes with no noticeable redistribution for up to 2 or 3 ps, being later redistributed in a cascade process at first to angular and then to radial distortions.
- Добавил в систему: Новаковская Юлия Вадимовна
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | expert_scan.pdf | expert_scan.pdf | 1,3 МБ | 18 декабря 2024 [NovakovskayaYV] | |
| 2. | Полный текст | PhysRevA.110.062815.pdf | 7,0 МБ | 18 декабря 2024 [NovakovskayaYV] |