| Autor: |
Andreev AS; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia., Baturo VV; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia., Lukashov SS; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia., Poretsky SA; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia., Pravilov AM; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia., Zhironkin AI; Department of Physics, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., Saint Petersburg 199034, Russia. |
| Abstrakt: |
We report on the results of spectroscopic studies of the HeNeI 2 van der Waals trimer using the two-step two-color HeNeI 2 (E0 g + , v E = 0-3 ←hν 2 B0 u + , v B = 19 ←hν 1 X0 g + , v X = 0) excitation scheme. The excitation spectra of the HeNeI 2 (B, E) decay product luminescence and the luminescence spectra of I 2 ion-pair states formed after HeNeI 2 (E) decay have been recorded and analyzed. The HeNeI 2 (X, B, E) binding energies have been estimated to be less than 111.8 cm -1 , 101.6 cm -1 , and 117.9 cm -1 , respectively. The HeNeI 2 (B, v B ) state decay has been found to be sequential with the formation of the HeI 2 (B, v B - 1) and NeI 2 (B, v B - 1) complexes without intermolecular excitation at the first step. An analysis of the HeNeI 2 (E) decay process based on the relative probabilities of the I 2 (D0 u + ) and I 2 (β1 g ) formation after decay, as well as vibrational populations of these states obtained from luminescence spectra, has also been performed. Calculations of the HeNeI 2 (X, B) vibrational energies using potential energy surfaces (PESs) of HeNeI 2 (X, B) constructed as a sum of the HeNe, HeI 2 , and NeI 2 potentials have been carried out. The values obtained agree well with the experimental estimations, and the observed transitions can be ascribed to the HeNeI 2 trimer of a tetrahedral geometry. Besides, a comparison of the PES constructed as a sum of the coupled-cluster single double triple [CCSD(T)] potentials with the PES based on the "direct" CCSD(T) calculations has been performed for the HeNeI 2 (X) trimer to verify the applicability of this representation to the trimer under study. |
