The diffuse scattering functions for two-dimensional model of KSCN cry
stal has been studied by the molecular-dynamics simulation technique.
We show that below the tetragonal orthorhombic phase transition the wi
dth of the diffuse peak remains temperature independent, although its
intensity increases when the temperature approaches T-c from below. Di
rect observations of crystal fluctuations indicate that with a rise in
temperature the size of fluctuations, which is of the order of four l
attice constants, remains constant but their density increases. These
simulations are in agreement with results of neutron scattering measur
ements.