The MD simulation of thermal properties of plutonium dioxide

Abstract The thermodynamic properties of PuO 2 have been investigated between 300 and 3000 K by molecular dynamics (MD) simulation with empirical interaction potential. The properties include melting point, lattice parameter variation, enthalpy and heat capacity. The melting point of two-phase simulation (TPS) is in agreement with the experimental value, and it gives a much lower value than one-phase simulation (OPS). The lattice parameter and heat capacity at high temperatures are expressed as a ( T ) = 5 . 38178 + 4.38 × 1 0 − 5 T + 6.5525 × 1 0 − 9 T 2 + 0.9362 × 1 0 − 12 T 3 and C P ( KJ ⋅ mol − 1 ⋅ K − 1 ) = 18648.8 e 474.5 / T / ( T 2 ( e 474.5 / T − 1 ) 2 ) + 9.337 × 10 − 6 T , respectively. True linear thermal expansion coefficient (TLTEC) α is about 8.89×10 −6  K −1 at 300 K. Our simulation results are in good agreement with experimental and other theoretical data.