Molecular Dynamics Studies of Minor Actinide Dioxides

Abstract

The molecular dynamics (MD) calculation was performed for minor actinide (MA: Np and Am) dioxides in the temperature range from 300 to 2,500 K to evaluate the thermophysical properties viz., the lattice parameter, thermal expansion coefficient, compressibility, heat capacity, and thermal conductivity. The Morse-type potential function added to the Busing-Ida type potential was employed for the ionic interactions. The interatomic potential parameters were determined by fitting to the experimental data of the lattice parameter. The usefulness and applicability of the MD method to evaluate the thermophysical properties of minor actinide dioxides were discussed.

A molecular dynamics study of the thermal properties of thorium oxide

“…The higher thermal expansion, calculated for the sample containing 10% uranium is still considerably less than that previously determined for urania, and for other oxide nuclear fuels, actinide oxides and other materials used in nuclear applications. 24,[26][27][28][29][30][31][32][33][34] This can be seen in Table III, which shows the values for the coefficient of linear expansion for the other materials varying between 5.0 Â 10 À6 K À1 and 2.8 Â 10 À5 K À1 . At worst the levels of thermal expansion of our systems are comparable to related materials and in most cases are significantly better.…”

A new modified Morse potential energy function for diatomic molecules

“…The Morse Potential [1] is the most widely accepted function used to describe the vibrational interaction between atoms in the diatomic molecules. The Morse function has been used in molecular spectroscopy [2] to calculate the transition frequencies and intensities of overtones of stretching of diatomic molecules and in molecular dynamics [3][4][5][6]. The Morse potential, when used to obtain the vibrational energy eigenvalues of diatomic molecules, shows a deviation from the experimentally observed values.…”

Force-field derivation and atomistic simulation of HMX–TATB–graphite mixture explosives

“…It is convenient to be used in molecular dynamics simulations. Other kinds of combinational potentials are used by Kurosaki, Dmitriev and Wunderlich for complicated material systems, such as AmO 2 , NpO 2 and Al 2 O 3 [36][37][38][39][40].…”