In the present study a novel pseudo-ion concept is introduced in the context of classical molecular dynamics simulation. It has been shown here that this approach can successfully predict the thermo-physical and thermo-mechanical properties of solid solution of two isostructural compounds. (U 0.8 Pu 0.2 )O 2 mixed oxide is taken as the model system to demonstrate the proposed model. Various physical properties of (U 0.8 Pu 0.2 )O 2 has been calculated which match the experimentally obtained data reasonably well. F. Wakai-contributing editor Manuscript No. 30376.