From: Adrian Roitberg <roitberg@qtp.ufl.edu>
Date: Mon, Nov 22, 2010 at 9:00 PM
Subject: Re: Hydrogen bond
To: Arunan <arunan@ipc.iisc.ernet.in>


Dear Arunan

I am reading the report now.

I have a couple of quick comments right away. Evidence of 'bonding' in H-bonds might look like a good idea, but I am afraid it would leave all theory out of it. Although some people would push for a true definition of 'bond' in quantum mechanics, there is simply no such thing/Quantum mechanics deals with electron probabilities, and maybe orbitals, depending on the level of theory. There is no objective definition of 'bonds' anywhere in quantum mechanics.

Now, in particular in my field (classical molecular dynamics in biomolecules), we use H-bond as a 'name' for instance for N-H...O-C interactions, but we could not, again by definition, provide evidence for that name, since bonding terms in classical mechanics are added ad hock.

I think this new definition would actually hurt as it is now.

Best regards
Adrian