  The dynamics of Lennard-Jones fluid is studied through extended mode coupling
theory (MCT) with the inclusion of the slow mode of defect density. Inclusion
of defect density facilitates the liquid like state for temperatures much lower
than predicted from ideal MCT. From the present model the temperature
dependence of the power law exponent is obtained at a {\em constant pressure}.
We have also computed the wave number dependence of the power law exponent.
