The MD simulation of thermal properties of plutonium dioxide

The thermodynamic properties of PuO2 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+4.38×10−5T+6.5525×10−9T2+0.9362×10−12T3a(T)=5.38178+4.38×10−5T+6.5525×10−9T2+0.9362×10−12T3 and CP(KJ⋅mol−1⋅K−1)=18648.8e474.5/T/(T2(e474.5/T−1)2)+9.337×10−6TCP(KJ⋅mol−1⋅K−1)=18648.8e474.5/T/(T2(e474.5/T−1)2)+9.337×10−6T, 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.