Bond critical point electronic kinetic energy density

Thus, if it is assumed that the local virial theorem is valid for the model electron densities fitted to the experimental structure factors, the kinetic, g(r), and potential, v(r), energy densities may be mapped, as well as the energy characteristics of the (3,-1) bond critical points evaluated [38]. 

In the following, this approach has been used to study the energy features of 3-NTO [29]. The kinetic, g(r), and potential, v(r), energy density maps have been calculated from the experimental electron densities with the WinXPRO program package [39] using the approach described above, as well as their difference with respect to atomic procrystals with no chemical bonds. Critical point characteristics have also been similarly analyzed. 

The first line lists the experimental result the second line- the atomic procrystal p is the electron density V2p is the Laplacian, g, v and he are the kinetic, potential and total electronic energies at the critical point R is the bond path length. 

Figure 6 shows a contour line diagram of the electron density distribution of the van der Waals complex Hcj (He,He distance 2.74 A). The electron density at the midpoint between the two He atoms is just 0.008 e/A, quite different from the values found for a typical covalent bond between first-row elements (1-5 e/A ). Despite the smallness of p(r) in the internuclear region, the He nuclei are linked by a MED path and the midpoint is the position of a (3, — 1) critical point (Fig. 6). As pointed out above this does not imply the existence of a chemical bond. The energy density H(r) is positive at the (3, — 1) critical point, which means that the kinetic energy rather than the potential energy dominates in the internuclear region. There is no chemical bond between the He atoms.

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