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He2 molecule

by khanhhung2512
Tags: molecule
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Aug3-14, 06:09 AM
Borek's Avatar
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Please don't post links to copyrighted material, I have replaced it with a link to acs abstract.

While it technically fits IUPAC definition of a molecule ("An electrically neutral entity consisting of more than one atom, with at least one vibrational state." - I assume there are vibrational states, I see no reason why there would be none), calling something with a binding energy of 95 neV "stable" doesn't make much sense to me. Typical bond energies are in the eV range, so they are tens of millions times stronger. Calling these dimers "stable" is a misnomer IMHO.

Edit: after reading the paper - no, it isn't a molecule. JChemEd paper clearly states that there are no excited states:

The He2 potential well can support just a single bound rotational–vibrational state (v = 0, J = 0) with an energy of approximately 1.176 mK. The dissociation energy of the molecule in its only rotational–vibrational state is smaller than the potential well depth by a factor of about 10-4. The bound state is just barely below the dissociation continuum threshold. The binding between two He atoms is so weak that even rotational excitation will result in dissociation.

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