  The mass spectra of quarkonium systems at temperature equal zero are analyzed
by solving the non-relativistic radial wave equation using the internal energy
potential. The QGP matter is studied through the dissociations of quarkonium
systems. A modified form of the internal energy potential function is used to
determine the EoS at different number of quark flavors by using Mayer s cluster
expansion theory and phenomenological thermodynamic model. The thermodynamic
model gives a good agreement with the lattice results rather than Mayer s
cluster expansion theory. One can conclude that, the Mayer s cluster expansion
theory may be more suitable to study a weakly coupled plasma while, the QGP may
be considered as a strongly interacting plasma.
