Chemistry Reference
In-Depth Information
Fig. 7 The benzene stacked
dimer:
filled squares
, total
energy;
open squares
,
atom-atom Coulombic
energy;
triangles
, correct
Coulombic energy. The ever
increasing trend of the
atom-atom energy is
obviously insensitive to the
choice of point charges
30
20
10
0
-10
-20
-30
2
3 4
inter-ring separation
5
Fig. 8 Calculated lattice
energies and experimental
heats of sublimation.
Squares
:
atom-atom,
circles
: PIXEL
results. kJ mol
1
units
4.6 Chemical Bonds Versus “Approach Preferences” in Crystals
The last sections have shown that the strength of chemical interactions can nowa-
days be evaluated rather easily and reliably, but is it possible, convenient, neces-
sary, or indispensable to define a chemical bond in a general conceptual way,
