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Updated: May 12, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Solvent states and spectroscopy of doped helium clusters as a quantum-chemistry-like problem
Néstor F Aguirre1, Pablo Villarreal, Gerardo Delgado-Barrio
1Instituto de Física Fundamental, CSIC, Serrano 123, 28006 Madrid, Spain.
Abstract:
The Full-Configuration-Interaction Nuclear-Orbital (FCI-NO) approach [J. Chem. Phys., 2009, 131, 19401], as the implementation of the quantum-chemistry ansatz, is overviewed and applied to (He)N-Cl2(X) clusters (N≤ 4). The ground and excited states of both fermionic (3)He and bosonic (4)He [see also, J. Phys. Chem. Lett., 2012, 2, 2145] clusters are studied. It is shown that the FCI-NO approach allows us to overcome three main difficulties: (1) the Fermi-Dirac (Bose-Einstein) nuclear statistics; (2) the wide (highly anharmonic) amplitudes of the He-dopant and He-He motions; and (3) both the weakly attractive (long-range) and the strongly repulsive (short-range) interaction between the helium atoms. Special emphasis is placed on the dependence of the cluster properties on the number of helium atoms, and on the comparison between the two helium isotopes. In particular, we analyze the analogies between quantum rings comprising electrons and (3)He atoms. The synthetic vibro-rotational Raman spectra of Cl2(X) immersed in ((3,4)He)N clusters (N≤ 4) are discussed as a function of the cluster size and the nuclear statistics. It is shown that the Coriolis couplings play a key role in modifying the spectral dopant profile in (3)He. Finally, we point out possible directions for future research using the quantum-chemistry ansatz.
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