In the present paper we have studied the superconducting parameters viz. electron-phonon coupling strength (ï¬), Coulomb pseudopotential (ï*) and transition temperature (Tc) of MgB2 on the basis of Mc. MillanÂs formalism.We have applied the HarrisonÂs first principle pseudopotential technique which has been a favorite theoretical framework within which various physical properties of metals and alloys have been studied since past decades. In this paper we have studied the impact of two different sets of core energy eigenvalues and observed that the measured transition temperature can be obtained through the choice of proper core energy eigenvalues (ïnl). Reasonable agreement has been obtained using Faber-Ziman formalism.