Bridging the gap between small clusters and nanodroplets: spectroscopic study and computer simulation of carbon dioxide solvated with helium atoms.
Description
<p>High resolution infrared spectra of HeN–CO2 clusters with N up to about 20 have been studied in the region of the CO2 v3 fundamental band. The B rotational constant initially drops as expected for a normal molecule, reaching a minimum for N = 5. Its subsequent rise for N = 6 to 11 can be interpreted as the transition from a normal (though floppy) molecule to a quantum solvation regime. For N > 13, the B value becomes approximately constant with a value about 17% larger than that measured in much larger helium nanodroplets. Quantum Monte Carlo calculations of pure rotational spectra are in excellent agreement with the measured B in this size range, and complement the experimental study with detailed structural information. For larger cluster size (N = 30-50) the simulations show a clear sign of convergence towards the nanodroplet B value.</p>
Journal
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- Physical Review Letters
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Physical Review Letters 92 (14), 145503-1, 2004-04
American Physical Society (APS)