Electron density and fused sphere model of the H-bonded glycine
conformer.
The electron density (6-31G*) is shown for the mirror plane of the molecule,
with color changes at
0.01, 0.02, ..., 0.10, 0.15, 0.20, ..., 0.60, 0.85, 1.10, ...,
3.10, and 5.00 electrons/Bohr³.
Saddle points in the electron density identify chemical bonds ( "What
is a bond?", R. F. W. Bader); the density
values in these points are a measure for the strength of the corresponding
bonds. According to this criterion,
the hydrogen bond therefore is a true chemical bond with a strength of
a few percent of a single bond. In the fused sphere model this weak
bond leads to a characteristic overlap of the respective spheres.
As a consequence of the hydrogen bond, the electron density around the
nitrogen atom is significantly polarized.
"What
is a bond?",
glycine.
Start of H-bond tour.
Quantum Chemistry Group.