skip to main content

Title: Theoretical investigation of the relative stability of Na{sup +}He{sub n} (n = 2–24) clusters: Many-body versus delocalization effects

The solvation of the Na{sup +} ion in helium clusters has been studied theoretically using optimization methods. A many-body empirical potential was developed to account for Na{sup +}–He and polarization interactions, and the most stable structures of Na{sup +}He{sub n} clusters were determined using the basin-hopping method. Vibrational delocalization was accounted for using zero-point energy corrections at the harmonic or anharmonic levels, the latter being evaluated from quantum Monte Carlo simulations for spinless particles. From the static perspective, many-body effects are found to play a minor role, and the structures obtained reflect homogeneous covering up to n = 10, followed by polyicosahedral packing above this size, the cluster obtained at n = 12 appearing particularly stable. The cationic impurity binds the closest helium atoms sufficiently to negate vibrational delocalization at small sizes. However, this snowball effect is obliterated earlier than shell completion, the nuclear wavefunctions of {sup 4}He{sub n}Na{sup +} with n = 5–7, and n > 10 already exhibiting multiple inherent structures. The decrease in the snowball size due to many-body effects is consistent with recent mass spectrometry measurements.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [1] ;  [4]
  1. Faculty of Sciences, Quantum Physics Laboratory, University of Monastir, Monastir 5079 (Tunisia)
  2. Faculty of Science, King Abdul-Aziz University, Jeddah (Saudi Arabia)
  3. University of Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble (France)
  4. (Saudi Arabia)
Publication Date:
OSTI Identifier:
22415320
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTERIZED SIMULATION; HELIUM; IMPURITIES; INTERACTIONS; MASS SPECTROSCOPY; MONTE CARLO METHOD; PARTICLES; POLARIZATION; SODIUM IONS; SOLVATION; STABILITY; WAVE FUNCTIONS