  Extensive Monte Carlo simulations are carried out to study thermal stability
of an infinite standalone silicon sheet. We used the Tersoff potential that has
been used with success for silicon at low temperatures. However, the melting
temperature $T_m$ calculated with the original parameters provided by Tersoff
is too high with respect to the experimental one. Agrawal, Raff and Komanduri
have proposed a modified set of parameters to reduce $T_m$. For comparison, we
have used these two sets of parameters to study the stability and the melting
of a standalone 2D sheet of silicon called "silicene", by analogy with graphene
for the carbon sheet. We find that 2D crystalline silicene is stable up to a
high temperature unlike in 2D systems with isotropic potentials such as
Lennard-Jones. The differences in the obtained results using two sets of
parameters are striking.
