This success also underscores the local character of these bond stretching vibrations.
Thursday, October 13, 2011
A concrete test of the Morse potential in a complex molecule
Just how accurate is the Morse potential? A key feature is the equidistance of adjacent energy levels.
This graph below illustrates the high quality of the Morse potential for describing a C=O bond within a protein. The data (taken from this PNAS paper) is via a technique which induces transitions from the v'th vibrational energy level to the (v+1) level.
Thus we see the Morse potential describes the true anharmonic potential at least up to v=7, which corresponds to energies of about 1.5 eV above that of the potential minimum.
This success also underscores the local character of these bond stretching vibrations.
This success also underscores the local character of these bond stretching vibrations.
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Is it something to do with breakdown of the Born-Oppenheimer approximation? In molecular spectroscopy you occasionally hear this term thro... -
Nitrogen fluoride (NF) seems like a very simple molecule and you would think it would very well understood, particularly as it is small enou... -
I welcome discussion on this point. I don't think it is as sensitive or as important a topic as the author order on papers. With rega...
Are you sure the second sentence here isn't about the harmonic oscillator, not the Morse oscillator. Don't the energy gaps get smaller as you go up the Morse oscillator?
ReplyDeleteI can reply since I was fooled in the same way,
ReplyDeletebut the reading carefully the caption of fig.1...
it is not the difference between the energy levels which is equidistant in the Morse potential, but the difference in consecutive transitions.