Environmental Engineering Reference
In-Depth Information
Figure 1.1
Schematic picture for Lennard-Jones potential.
potential isat
2
A
B
1
/
6
2
1
/
6
r
0
=
σ
=
,
(1.4)
and the well depth is
B
2
4
A
.
ε
=
(1.5)
Moreover, LJ potential vanishes when the interatomic distance
is greater than 2.5
σ
, which can be used as the cut-off distance in
practical simulations to reduce the computer time for force field
calculations.
LJ potential is often used to describe the properties of gases,
simple fluids, and is particularly accurate for noble gas atoms. It is
not able to account for the directional nature or the environmental
dependence of the bond in many solid state systems where many-
body effect is important. Therefore, LJ potential is not suitable
to model systems with practical interest, such as semiconductors.
For such systems a more complex many-body potential should be
