ISSN:
1434-6079
Keywords:
31.20.T
;
35.20.G
;
36.40
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract SCF and CEPA calculations are applied to study the structure of small He cluster ions, He n + ,n=2, 3, 4, 5 and some low-lying Rydberg states of He4. The effect of electron correlation upon the equilibrium structures and binding energies is discussed. He 3 + has a linear symmetric equilibrium geometry with a bond length of 2.35a 0 and a binding energyD e =0.165 eV with respect to He 2 + +He (experimentally:D 0=0.17 eV which corresponds toD e ≈0.20 eV). He 4 + is a very floppy molecular ion with several energetically very similar geometrical configurations. Our CEPA calculations yield a T-shaped form with a He 3 + centre (R e = 2.35a 0) and one inductively bound He atom (4.39a 0 from the central He atom of He 3 + ) as equilibrium structure. Its binding energy with respect to He 3 + +He is 0.031 eV. A linear symmetric configuration consisting of a He 2 + centre with a bond length of 2.10a 0 and two inductively bound He atoms (4.20a 0 from the centre of He 2 + ) is only 0.02–0.03 eV higher in energy. We expect that in larger He cluster ions structures with He 2 + and He 3 + centres andn−2 orn−3 inductively bound He atoms have nearly the same energies. In He4 a low-lying metastable Rydberg state (3 Π symmetry for linear He 4 * ,3 B 1 for the T-shaped form) exists which is slightly stronger bound with respect to He 3 * +He than the corresponding ion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01437335
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