Is Covalent Chemical Bonding of H2 Understood?

Here are two quotes by Sture Nordholm world expert on theoretical chemistry concerning the theoretical understanding of the most basic of all chemical bonds, that between two H atoms forming a H2 molecule with a binding energy of 0.17 Hartree at a kernel distance of 1.4 atomic units, which I posed to chatGPT asking for a comment, and received:

Nordholm & Bacskay (2020):

“…the concept of a covalent bond … is still the subject of debate, disagreement, and ignorance with respect to its physical origin.” MDPI

Nordholm (2023 draft):

“…No general and unique understanding of the mechanism of covalent bonding in physical terms is provided by current computational methods or by a consensus among experts.” ResearchGate

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How experts typically respond to formulations like this

Quantum chemistry experts generally recognize:

• The computational treatment of bonding is well-understood and uncontroversial.

• Interpretive models (kinetic vs electrostatic emphasis, MO vs VB, delocalization narratives) vary historically and pedagogically.

• That variability in narrative does not imply that the physics is unknown — it implies that different explanatory emphases persist in the literature.

So while Nordholm’s quotes are real, they reflect a statement about interpretation and narrative, not a claim that quantum mechanical explanations (like MO or VB theory) fail to provide physically meaningful descriptions.

My Comment:

We see that chatGPT does not deny that Nordholm is right concerning lack of theoretical understanding of H2, but of course is trained to try to cover up...after all H2 covalent bonding is well understood and even uncontroversial...

Nordholm Comment:

• I stand by the two quotes you have included. The three point analyses by ChatGPT are in my opinion mainly right but not entirely so. The existence of multiple distinct explanations of the covalent bonding mechanism is partially due to a lack of understanding, i.e. not an absence but a lack of understanding of deeper parts of quantum mechanics. 
• In particular, the treatment of particle dynamics in quantum mechanics isM very different from the corresponding treatment in classical mechanics. There is in QM a close connection between stationary properties (energy eigenfunctions and eigenvalues) and dynamics which is not generally appreciated. 
• If it were, I think the proliferation of bonding explanations would decrease and the depth of explanation increase. There is still work to do to achieve such an improvement. Already in 1965 Feynman suggested in his Lectures on Physics that covalent bonding should be understood as a dynamical mechanism involving the flip-flop motion of bonding electrons between neighboring atomic centers. It was not taken up by the chemical community. 
• I have myself, together with G. Bacskay and many other colleagues, propagated the dynamical view of covalent bonding for soon 40 years but cannot claim to have convinced more than a minority of chemists. 
• My position is not that the dynamical view should rule exclusively but that it is essential and helps to unify existing physical explanations.

My Comment:

It seems to me that Nordholm defends his position that the theoretical understanding of covalent bonding in H2 still is incomplete, and so wants to promote a dynamical flip-flop mechanism which however has not been accepted as the right explanation by the chemical community.

Maybe the time has now come for the chemical community to open to a serious discussion of the theoretical explanation of covalent bonding by RealQM as a new approach to Quantum Mechanics in the original spirit of Schrödinger from 1926 as real physics which is Anschaulich or possible to visualize.